<SUBMISSION>
<ACCESSION-NUMBER>0001002014-12-000277
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20120514
<FILING-DATE>20120517
<DATE-OF-FILING-DATE-CHANGE>20120517
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>Chan Sidney
<CIK>0001308120
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-30414
<FILM-NUMBER>12851320
</FILING-VALUES>
<MAIL-ADDRESS>
<STREET1>114M REYNOLDA VILLAGE
<CITY>WINSTON-SALEM
<STATE>NC
<ZIP>27106
</MAIL-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>ALR TECHNOLOGIES INC.
<CIK>0001087022
<ASSIGNED-SIC>3669
<IRS-NUMBER>880225807
<STATE-OF-INCORPORATION>NV
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>7400 BEAUFONT SPRINGS DRIVE
<STREET2>SUITE 300
<CITY>RICHMOND
<STATE>VA
<ZIP>23225
<PHONE>(804) 554-3500
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>7400 BEAUFONT SPRINGS DRIVE
<STREET2>SUITE 300
<CITY>RICHMOND
<STATE>VA
<ZIP>23225
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>ALR TECHNOLOGIES INC
<DATE-CHANGED>19990524
</FORMER-COMPANY>
</ISSUER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0305</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2012-05-14</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001087022</issuerCik>
        <issuerName>ALR TECHNOLOGIES INC.</issuerName>
        <issuerTradingSymbol>ALRT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001308120</rptOwnerCik>
            <rptOwnerName>Chan Sidney</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>23H BLOCK III RIVIERA GARDEN</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>TSUEN WAN, NEW TERRITORIES</rptOwnerCity>
            <rptOwnerState>K3</rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription>HONG KONG</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2012-05-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>300000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>98498482</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Previously had reported 300,000 shares owned by my children as beneficially owned for me. My children are all over the age of 21 and live at a separate address. As a result, their shares are no longer deemed as owned for my benefit.</footnote>
        <footnote id="F2">14,845,000 shares are held in the name of Sidney Chan, 500,000 shares are held in the name of KRS Retraction Limited, and, 83,153,482 are owned by Christine Kan, Mr. Chan's wife.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>SIDNEY CHAN</signatureName>
        <signatureDate>2012-05-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
