<?xml version="1.0" encoding="us-ascii"?>
<!-- DFIN ActiveDisclosure(SM) XBRL Schema Document - http://www.dfinsolutions.com/ -->
<!-- Creation Date      : 2019-11-05T01:45:05.8707604+00:00 -->
<!-- Version            : 5.0.0.208 -->
<!-- Package ID         : aac34cf1253d4040b7847231c6aeb265 -->
<!-- Copyright (c) 2019 Donnelley Financial Solutions, Inc. All Rights Reserved. -->
<xsd:schema xmlns:nonnum="http://www.xbrl.org/dtr/type/non-numeric" xmlns:num="http://www.xbrl.org/dtr/type/numeric" xmlns:sic="http://xbrl.sec.gov/sic/2011-01-31" xmlns:stpr="http://xbrl.sec.gov/stpr/2018-01-31" xmlns:naics="http://xbrl.sec.gov/naics/2017-01-31" xmlns:invest="http://xbrl.sec.gov/invest/2013-01-31" xmlns:srt-types="http://fasb.org/srt-types/2019-01-31" xmlns:achv="http://achievelifesciences.com/20190930" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:srt="http://fasb.org/srt/2019-01-31" xmlns:us-gaap="http://fasb.org/us-gaap/2019-01-31" xmlns:dei="http://xbrl.sec.gov/dei/2019-01-31" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:country="http://xbrl.sec.gov/country/2017-01-31" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:currency="http://xbrl.sec.gov/currency/2019-01-31" xmlns:us-types="http://fasb.org/us-types/2019-01-31" xmlns:exch="http://xbrl.sec.gov/exch/2019-01-31" attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://achievelifesciences.com/20190930" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <xsd:import schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd" namespace="http://www.xbrl.org/2003/instance" />
  <xsd:import schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" namespace="http://www.xbrl.org/2003/linkbase" />
  <xsd:import schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd" namespace="http://xbrl.org/2005/xbrldt" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/country/2017/country-2017-01-31.xsd" namespace="http://xbrl.sec.gov/country/2017-01-31" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/currency/2019/currency-2019-01-31.xsd" namespace="http://xbrl.sec.gov/currency/2019-01-31" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd" namespace="http://xbrl.sec.gov/dei/2019-01-31" />
  <xsd:import schemaLocation="http://www.xbrl.org/dtr/type/nonNumeric-2009-12-16.xsd" namespace="http://www.xbrl.org/dtr/type/non-numeric" />
  <xsd:import schemaLocation="http://www.xbrl.org/dtr/type/numeric-2009-12-16.xsd" namespace="http://www.xbrl.org/dtr/type/numeric" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/exch/2019/exch-2019-01-31.xsd" namespace="http://xbrl.sec.gov/exch/2019-01-31" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd" namespace="http://xbrl.sec.gov/invest/2013-01-31" />
  <xsd:import schemaLocation="http://www.xbrl.org/lrr/arcrole/factExplanatory-2009-12-16.xsd" namespace="http://www.xbrl.org/2009/arcrole/fact-explanatoryFact" />
  <xsd:import schemaLocation="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd" namespace="http://www.xbrl.org/2009/role/negated" />
  <xsd:import schemaLocation="http://www.xbrl.org/lrr/role/net-2009-12-16.xsd" namespace="http://www.xbrl.org/2009/role/net" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/naics/2017/naics-2017-01-31.xsd" namespace="http://xbrl.sec.gov/naics/2017-01-31" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/sic/2011/sic-2011-01-31.xsd" namespace="http://xbrl.sec.gov/sic/2011-01-31" />
  <xsd:import schemaLocation="http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd" namespace="http://fasb.org/srt/2019-01-31" />
  <xsd:import schemaLocation="http://xbrl.fasb.org/srt/2019/elts/srt-roles-2019-01-31.xsd" namespace="http://fasb.org/srt-roles/2019-01-31" />
  <xsd:import schemaLocation="http://xbrl.fasb.org/srt/2019/elts/srt-types-2019-01-31.xsd" namespace="http://fasb.org/srt-types/2019-01-31" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/stpr/2018/stpr-2018-01-31.xsd" namespace="http://xbrl.sec.gov/stpr/2018-01-31" />
  <xsd:import schemaLocation="http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd" namespace="http://fasb.org/us-gaap/2019-01-31" />
  <xsd:import schemaLocation="http://xbrl.fasb.org/us-gaap/2019/elts/us-roles-2019-01-31.xsd" namespace="http://fasb.org/us-roles/2019-01-31" />
  <xsd:import schemaLocation="http://xbrl.fasb.org/us-gaap/2019/elts/us-types-2019-01-31.xsd" namespace="http://fasb.org/us-types/2019-01-31" />
  <xsd:annotation>
    <xsd:appinfo>
      <link:roleType id="TemplateLink" roleURI="http://achievelifesciences.com/20190930/role/TemplateLink" xmlns:link="http://www.xbrl.org/2003/linkbase">
        <link:definition>00000 - Document - Template Link</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="achv-20190930_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:title="Calculation Links, all" xlink:type="simple" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" />
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="achv-20190930_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:title="Definition Links, all" xlink:type="simple" />
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="achv-20190930_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:title="Label Links, all" xlink:type="simple" />
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="achv-20190930_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:title="Presentation Links, all" xlink:type="simple" />
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DocumentDocumentAndEntityInformation" id="Role_DocumentDocumentAndEntityInformation">
        <link:definition>100000 - Document - Document and Entity Information</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/StatementConsolidatedBalanceSheetsUnaudited" id="Role_StatementConsolidatedBalanceSheetsUnaudited">
        <link:definition>100010 - Statement - Consolidated Balance Sheets (Unaudited)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/StatementConsolidatedBalanceSheetsParentheticalUnaudited" id="Role_StatementConsolidatedBalanceSheetsParentheticalUnaudited">
        <link:definition>100020 - Statement - Consolidated Balance Sheets (Parenthetical) (Unaudited)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/StatementConsolidatedStatementsOfLossAndComprehensiveLossUnaudited" id="Role_StatementConsolidatedStatementsOfLossAndComprehensiveLossUnaudited">
        <link:definition>100030 - Statement - Consolidated Statements of Loss and Comprehensive Loss (Unaudited)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/StatementConsolidatedStatementsOfCashFlowsUnaudited" id="Role_StatementConsolidatedStatementsOfCashFlowsUnaudited">
        <link:definition>100040 - Statement - Consolidated Statements of Cash Flows (Unaudited)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/StatementConsolidatedStatementsOfStockholderSEquityUnaudited" id="Role_StatementConsolidatedStatementsOfStockholderSEquityUnaudited">
        <link:definition>100050 - Statement - Consolidated Statements of Stockholder&apos;s Equity (Unaudited)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureNatureOfBusinessBasisOfPresentationAndGoingConcernUncertainty" id="Role_DisclosureNatureOfBusinessBasisOfPresentationAndGoingConcernUncertainty">
        <link:definition>100060 - Disclosure - Nature of Business, Basis of Presentation and Going Concern Uncertainty</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureAccountingPolicies" id="Role_DisclosureAccountingPolicies">
        <link:definition>100070 - Disclosure - Accounting Policies</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureIntangibles" id="Role_DisclosureIntangibles">
        <link:definition>100080 - Disclosure - Intangibles</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureLicenseAgreements" id="Role_DisclosureLicenseAgreements">
        <link:definition>100090 - Disclosure - License Agreements</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureFairValueMeasurements" id="Role_DisclosureFairValueMeasurements">
        <link:definition>100100 - Disclosure - Fair Value Measurements</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureCommonStock" id="Role_DisclosureCommonStock">
        <link:definition>100110 - Disclosure - Common Stock</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureCommitmentsAndContingencies" id="Role_DisclosureCommitmentsAndContingencies">
        <link:definition>100120 - Disclosure - Commitments and Contingencies</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureAccountingPoliciesPolicies" id="Role_DisclosureAccountingPoliciesPolicies">
        <link:definition>100130 - Disclosure - Accounting Policies (Policies)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureIntangiblesTables" id="Role_DisclosureIntangiblesTables">
        <link:definition>100140 - Disclosure - Intangibles (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureFairValueMeasurementsTables" id="Role_DisclosureFairValueMeasurementsTables">
        <link:definition>100150 - Disclosure - Fair Value Measurements (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureCommonStockTables" id="Role_DisclosureCommonStockTables">
        <link:definition>100160 - Disclosure - Common Stock (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureCommitmentsAndContingenciesTables" id="Role_DisclosureCommitmentsAndContingenciesTables">
        <link:definition>100170 - Disclosure - Commitments and Contingencies (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureNatureOfBusinessBasisOfPresentationAndGoingConcernUncertaintyAdditionalInformationDetail" id="Role_DisclosureNatureOfBusinessBasisOfPresentationAndGoingConcernUncertaintyAdditionalInformationDetail">
        <link:definition>100180 - Disclosure - Nature of Business, Basis of Presentation and Going Concern Uncertainty - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureIntangiblesAdditionalInformationDetail" id="Role_DisclosureIntangiblesAdditionalInformationDetail">
        <link:definition>100190 - Disclosure - Intangibles - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureIntangiblesComponentsOfIntangibleAssetsDetail" id="Role_DisclosureIntangiblesComponentsOfIntangibleAssetsDetail">
        <link:definition>100200 - Disclosure - Intangibles - Components of Intangible Assets (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureIntangiblesEstimatedFutureAmortizationExpenseRelatedToIntangibleAssetsDetail" id="Role_DisclosureIntangiblesEstimatedFutureAmortizationExpenseRelatedToIntangibleAssetsDetail">
        <link:definition>100210 - Disclosure - Intangibles - Estimated Future Amortization Expense Related to Intangible Assets (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureLicenseAgreementsAdditionalInformationDetail" id="Role_DisclosureLicenseAgreementsAdditionalInformationDetail">
        <link:definition>100220 - Disclosure - License Agreements - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureFairValueMeasurementsAdditionalInformationDetail" id="Role_DisclosureFairValueMeasurementsAdditionalInformationDetail">
        <link:definition>100230 - Disclosure - Fair Value Measurements - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureFairValueMeasurementsSummaryOfAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetail" id="Role_DisclosureFairValueMeasurementsSummaryOfAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetail">
        <link:definition>100240 - Disclosure - Fair Value Measurements - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureFairValueMeasurementsSummaryOfCashCashEquivalentsAndShortTermInvestmentsDetail" id="Role_DisclosureFairValueMeasurementsSummaryOfCashCashEquivalentsAndShortTermInvestmentsDetail">
        <link:definition>100250 - Disclosure - Fair Value Measurements - Summary of Cash, Cash Equivalents and Short-Term Investments (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureCommonStockAuthorizedAdditionalInformationDetail" id="Role_DisclosureCommonStockAuthorizedAdditionalInformationDetail">
        <link:definition>100260 - Disclosure - Common Stock - Authorized - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureCommonStockIssuedAndOutstandingSharesAdditionalInformationDetail" id="Role_DisclosureCommonStockIssuedAndOutstandingSharesAdditionalInformationDetail">
        <link:definition>100270 - Disclosure - Common Stock - Issued and Outstanding Shares - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureCommonStockStockOptionsAdditionalInformationDetail" id="Role_DisclosureCommonStockStockOptionsAdditionalInformationDetail">
        <link:definition>100280 - Disclosure - Common Stock - Stock Options - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureCommonStockSummaryOfStockOptionsActivityDetail" id="Role_DisclosureCommonStockSummaryOfStockOptionsActivityDetail">
        <link:definition>100290 - Disclosure - Common Stock - Summary of Stock Options Activity (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureCommonStockSummaryOfFairValueOfEachStockAwardForEmployeesAndDirectorsDetail" id="Role_DisclosureCommonStockSummaryOfFairValueOfEachStockAwardForEmployeesAndDirectorsDetail">
        <link:definition>100300 - Disclosure - Common Stock - Summary of Fair Value of Each Stock Award for Employees and Directors (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureCommonStockSummaryOfShareBasedCompensationExpenseForStockOptionsAndRestrictedStockDetail" id="Role_DisclosureCommonStockSummaryOfShareBasedCompensationExpenseForStockOptionsAndRestrictedStockDetail">
        <link:definition>100310 - Disclosure - Common Stock - Summary of Share-Based Compensation Expense for Stock Options and Restricted Stock (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureCommonStockRestrictedStockUnitAwardsAdditionalInformationDetail" id="Role_DisclosureCommonStockRestrictedStockUnitAwardsAdditionalInformationDetail">
        <link:definition>100320 - Disclosure - Common Stock - Restricted Stock Unit Awards - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureCommonStockSummaryOfRestrictedStockUnitAwardActivityDetail" id="Role_DisclosureCommonStockSummaryOfRestrictedStockUnitAwardActivityDetail">
        <link:definition>100330 - Disclosure - Common Stock - Summary of Restricted Stock Unit Award Activity (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureCommonStockCommonStockWarrantsAdditionalInformationDetail" id="Role_DisclosureCommonStockCommonStockWarrantsAdditionalInformationDetail">
        <link:definition>100340 - Disclosure - Common Stock - Common Stock Warrants - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureCommonStockSummaryOfOutstandingWarrantsDetail" id="Role_DisclosureCommonStockSummaryOfOutstandingWarrantsDetail">
        <link:definition>100350 - Disclosure - Common Stock - Summary of Outstanding Warrants (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureCommitmentsAndContingenciesSummaryOfContractualObligationsDetail" id="Role_DisclosureCommitmentsAndContingenciesSummaryOfContractualObligationsDetail">
        <link:definition>100360 - Disclosure - Commitments and Contingencies - Summary of Contractual Obligations (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureCommitmentsAndContingenciesAdditionalInformationDetail" id="Role_DisclosureCommitmentsAndContingenciesAdditionalInformationDetail">
        <link:definition>100370 - Disclosure - Commitments and Contingencies - Additional Information (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureCommitmentsAndContingenciesSummaryOfFutureMinimumAnnualLeasePaymentsDetail" id="Role_DisclosureCommitmentsAndContingenciesSummaryOfFutureMinimumAnnualLeasePaymentsDetail">
        <link:definition>100380 - Disclosure - Commitments and Contingencies - Summary of Future Minimum Annual Lease Payments (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://achievelifesciences.com/20190930/taxonomy/role/DisclosureCommitmentsAndContingenciesSummaryOfOtherInformationRelatedToLeasesDetail" id="Role_DisclosureCommitmentsAndContingenciesSummaryOfOtherInformationRelatedToLeasesDetail">
        <link:definition>100390 - Disclosure - Commitments and Contingencies - Summary of Other Information Related to Leases (Detail)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
    </xsd:appinfo>
  </xsd:annotation>
  <xsd:element id="achv_AccruedLiabilitiesClinicalCurrent" name="AccruedLiabilitiesClinicalCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="achv_IncreaseDecreaseInAccruedClinicalLiabilities" name="IncreaseDecreaseInAccruedClinicalLiabilities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="achv_ProceedsFromEquityFinancingNetOfIssuanceCost" name="ProceedsFromEquityFinancingNetOfIssuanceCost" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="achv_StockIssuedDuringPeriodSharesWarrantsExercised" name="StockIssuedDuringPeriodSharesWarrantsExercised" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_StockIssuedDuringPeriodValueWarrantsExercised" name="StockIssuedDuringPeriodValueWarrantsExercised" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="achv_StockIssuedDuringPeriodSharesPreferredShareConversion" name="StockIssuedDuringPeriodSharesPreferredShareConversion" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_StockIssuedDuringPeriodValuePreferredShareConversion" name="StockIssuedDuringPeriodValuePreferredShareConversion" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="achv_LincolnParkCapitalFundLLCMember" name="LincolnParkCapitalFundLLCMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_PublicOfferingMember" name="PublicOfferingMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_SeattleOfficeOperatingLeaseMember" name="SeattleOfficeOperatingLeaseMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_ScheduleOfSupplementalCashFlowsInformationRelatedToLeasesTableTextBlock" name="ScheduleOfSupplementalCashFlowsInformationRelatedToLeasesTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_WorkingCapitalBalance" name="WorkingCapitalBalance" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="achv_LicenseAgreementExpiryDate" name="LicenseAgreementExpiryDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_SopharmaMember" name="SopharmaMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_UniversityOfBristolMember" name="UniversityOfBristolMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_LicenseAgreementMember" name="LicenseAgreementMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_AmendmentToLicenseAgreementMember" name="AmendmentToLicenseAgreementMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_PatentExpiryDate" name="PatentExpiryDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_MaximumRequiredPaymentUnderLicenseAgreementUponCompletionOfVariousMilestones" name="MaximumRequiredPaymentUnderLicenseAgreementUponCompletionOfVariousMilestones" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="achv_PaymentsUnderLicenseAgreement" name="PaymentsUnderLicenseAgreement" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="achv_LicenseAgreementExpiryMonth" name="LicenseAgreementExpiryMonth" type="xbrli:gYearMonthItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_VolumeOfCytisineProvidedUnderLicenseAgreement" name="VolumeOfCytisineProvidedUnderLicenseAgreement" type="num:massItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_MaturityPeriodOfSecurities" name="MaturityPeriodOfSecurities" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_RestrictedCashMember" name="RestrictedCashMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_MaximumMaturityPeriodOfCashAndCashEquivalents" name="MaximumMaturityPeriodOfCashAndCashEquivalents" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_MaximumMaturityPeriodOfShortTermInvestments" name="MaximumMaturityPeriodOfShortTermInvestments" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_RightToSellCommonStockSharesAsPerPurchaseAgreementMaximum" name="RightToSellCommonStockSharesAsPerPurchaseAgreementMaximum" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="achv_MinimumPercentageOfCommonStockSharesOutstandingAuthorizedToSell" name="MinimumPercentageOfCommonStockSharesOutstandingAuthorizedToSell" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_LincolnParkCapitalFundLimitedLiabilityCompanyMember" name="LincolnParkCapitalFundLimitedLiabilityCompanyMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_UnitsMember" name="UnitsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_OtherWarrantSharesMember" name="OtherWarrantSharesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_PurchaseAgreementMember" name="PurchaseAgreementMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_ClassAUnitsMember" name="ClassAUnitsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_ClassBUnitsMember" name="ClassBUnitsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_SeriesAConvertiblePreferredStockMember" name="SeriesAConvertiblePreferredStockMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_LadenburgThalmannAndCoIncMember" name="LadenburgThalmannAndCoIncMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_DirectOfferingMember" name="DirectOfferingMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_HCWainwrightCoLLCMember" name="HCWainwrightCoLLCMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_PurchaseOfStockNumberOfSharesPurchasedInTransaction" name="PurchaseOfStockNumberOfSharesPurchasedInTransaction" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_StockAndWarrantsIssuedDuringPeriodSharesWarrants" name="StockAndWarrantsIssuedDuringPeriodSharesWarrants" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="achv_CommonStockAdditionalSharesToBeIssuedValueAuthorizedMaximum" name="CommonStockAdditionalSharesToBeIssuedValueAuthorizedMaximum" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="achv_SaleOfStockNumberOfAdditionalSharesToBeIssuedInTransactionMaximum" name="SaleOfStockNumberOfAdditionalSharesToBeIssuedInTransactionMaximum" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="achv_ProceedsFromIssuanceOfCommonStockGross" name="ProceedsFromIssuanceOfCommonStockGross" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="achv_CommonStockSharesAvailableForFutureGrant" name="CommonStockSharesAvailableForFutureGrant" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="achv_StockAndWarrantsIssuedDuringPeriodPublicOffering" name="StockAndWarrantsIssuedDuringPeriodPublicOffering" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_SaleOfStockPricePerUnit" name="SaleOfStockPricePerUnit" type="num:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="achv_StockUnitsDescription" name="StockUnitsDescription" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_ClassOfWarrantOrRightExercisePeriod" name="ClassOfWarrantOrRightExercisePeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_ClassOfWarrantOrRightCancellationDescription" name="ClassOfWarrantOrRightCancellationDescription" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_NumberOfRequiredConsecutiveDaysWeightedAverageTradingPriceForCancelationOrRecallOfWarrants" name="NumberOfRequiredConsecutiveDaysWeightedAverageTradingPriceForCancelationOrRecallOfWarrants" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_MinimumRequiredTradingPricePercentageOverExercisePriceForCancelationOrRecallOfWarrants" name="MinimumRequiredTradingPricePercentageOverExercisePriceForCancelationOrRecallOfWarrants" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_MinimumRequiredTradingVolumeValuePerDayForCancelationOrRecallOfWarrants" name="MinimumRequiredTradingVolumeValuePerDayForCancelationOrRecallOfWarrants" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="achv_PeriodGrantedForUnderwritingOption" name="PeriodGrantedForUnderwritingOption" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_OverAllotmentOptionExerciseDate" name="OverAllotmentOptionExerciseDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_SaleOfStockAndWarrantsNumberOfAdditionalSharesToBeIssuedInTransactionMaximum" name="SaleOfStockAndWarrantsNumberOfAdditionalSharesToBeIssuedInTransactionMaximum" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="achv_GrossProceedsFromSaleOfWarrantsAndUnits" name="GrossProceedsFromSaleOfWarrantsAndUnits" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="achv_WarrantAndUnitsOfferingCostIncludingUnderwritingDiscountsAndCommissions" name="WarrantAndUnitsOfferingCostIncludingUnderwritingDiscountsAndCommissions" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="achv_NetProceedsFromSaleOfWarrantsAndUnits" name="NetProceedsFromSaleOfWarrantsAndUnits" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="achv_MaximumNumberOfCommonSharesIssuablePerWarrantUponConversion" name="MaximumNumberOfCommonSharesIssuablePerWarrantUponConversion" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_GrossProceedsFromIssuanceOfCommonStock" name="GrossProceedsFromIssuanceOfCommonStock" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="achv_PlacementAgentFeesAndOfferingExpenses" name="PlacementAgentFeesAndOfferingExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="achv_PercentageOfCommissionOnProceedsFromSaleOfCommonStock" name="PercentageOfCommissionOnProceedsFromSaleOfCommonStock" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_TwoThousandAndEighteenEquityIncentivePlanMember" name="TwoThousandAndEighteenEquityIncentivePlanMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_EmployeesAndConsultantsMember" name="EmployeesAndConsultantsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_BoardOfDirectorsMember" name="BoardOfDirectorsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_TwoThousandsAndSeventeenEquityIncentivePlanMember" name="TwoThousandsAndSeventeenEquityIncentivePlanMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_TwoThousandsAndTenPerformanceIncentivePlanMember" name="TwoThousandsAndTenPerformanceIncentivePlanMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_ArmisticeCapitalMasterFundLtdMember" name="ArmisticeCapitalMasterFundLtdMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_October2018EquityFinancingMember" name="October2018EquityFinancingMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_June2018EquityFinancingMember" name="June2018EquityFinancingMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_NewWarrantMember" name="NewWarrantMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_WarrantsIssuedInJuneTwoThousandEighteenMember" name="WarrantsIssuedInJuneTwoThousandEighteenMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_WarrantsIssuedInOctoberTwoThousandEighteenMember" name="WarrantsIssuedInOctoberTwoThousandEighteenMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_FairValueOfWarrantsRecognizedIntoRetainedEarningsAccumulatedDeficit" name="FairValueOfWarrantsRecognizedIntoRetainedEarningsAccumulatedDeficit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="achv_ClassOfWarrantsOrRightExpirationDate" name="ClassOfWarrantsOrRightExpirationDate" type="xbrli:gYearMonthItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_SeriesAOneUnitsMember" name="SeriesAOneUnitsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_WarrantsIssuedInSeptemberTwoThousandSeventeenMember" name="WarrantsIssuedInSeptemberTwoThousandSeventeenMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_WarrantsIssuedInMayTwoThousandNinteenMember" name="WarrantsIssuedInMayTwoThousandNinteenMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_NumberOfWarrantsExercised" name="NumberOfWarrantsExercised" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_ContractualObligationFiscalYearMaturityScheduleLineItems" name="ContractualObligationFiscalYearMaturityScheduleLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_ContractualObligationFiscalYearMaturityScheduleTable" name="ContractualObligationFiscalYearMaturityScheduleTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_VancouverOfficeOperatingLeaseMember" name="VancouverOfficeOperatingLeaseMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_ExpirationOfOperatingLeaseAgreement" name="ExpirationOfOperatingLeaseAgreement" type="xbrli:gYearMonthItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_PikeMember" name="PikeMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_LeaseAgreementCommencementDate" name="LeaseAgreementCommencementDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_AreaOfOfficeSpaceLeased" name="AreaOfOfficeSpaceLeased" type="num:areaItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_OperatingLeaseInitialMonthlyBaseRentExpenses" name="OperatingLeaseInitialMonthlyBaseRentExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="achv_OperatingLeaseRevisedMonthlyBaseRentExpenses" name="OperatingLeaseRevisedMonthlyBaseRentExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="achv_OperatingLeaseConstructionAllowance" name="OperatingLeaseConstructionAllowance" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="achv_MonthlyBaseRentalPayments" name="MonthlyBaseRentalPayments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="achv_MonthlyBaseRentalPaymentsMaximumAnnualIncrease" name="MonthlyBaseRentalPaymentsMaximumAnnualIncrease" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="achv_LeaseSecurityDepositAnnualPayment" name="LeaseSecurityDepositAnnualPayment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="achv_LeaseSecurityDepositAnnualDecrease" name="LeaseSecurityDepositAnnualDecrease" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="achv_PercentageProfitAttributableToLessor" name="PercentageProfitAttributableToLessor" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="achv_PropertySubleasePercentageTerminationEligibility" name="PropertySubleasePercentageTerminationEligibility" type="num:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="achv_RightOfUseAssetsObtainedInExchangeForLeaseObligationsAbstract" name="RightOfUseAssetsObtainedInExchangeForLeaseObligationsAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="achv_IndemnificationExpense" name="IndemnificationExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
</xsd:schema>
