<SEC-DOCUMENT>0001562180-15-000728.txt : 20150904
<SEC-HEADER>0001562180-15-000728.hdr.sgml : 20150904
<ACCEPTANCE-DATETIME>20150904160322
ACCESSION NUMBER:		0001562180-15-000728
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20150902
FILED AS OF DATE:		20150904
DATE AS OF CHANGE:		20150904

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Tokai Pharmaceuticals Inc
		CENTRAL INDEX KEY:			0001404281
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		255 STATE STREET
		STREET 2:		6TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02109
		BUSINESS PHONE:		617-225-4348

	MAIL ADDRESS:	
		STREET 1:		255 STATE STREET
		STREET 2:		6TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02109

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Kalowski Lee
		CENTRAL INDEX KEY:			0001618273

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36620
		FILM NUMBER:		151094648

	MAIL ADDRESS:	
		STREET 1:		C/O TOKAI PHARMACEUTICALS, INC.
		STREET 2:		ONE BROADWAY, 14TH FLOOR
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02142
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primarydocument.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2015-09-02</periodOfReport>

    <notSubjectToSection16>false</notSubjectToSection16>

    <issuer>
        <issuerCik>0001404281</issuerCik>
        <issuerName>Tokai Pharmaceuticals Inc</issuerName>
        <issuerTradingSymbol>TKAI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001618273</rptOwnerCik>
            <rptOwnerName>Kalowski Lee</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O TOKAI PHARMACEUTICALS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>255 STATE STREET 6TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02109</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>false</isDirector>
            <isOfficer>true</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle>Chief Financial Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2015-09-02</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2158.00</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>12.96</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>45621.00</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Shares were sold to satisfy certain tax obligations of the Reporting Person triggered by the vesting of certain restricted stock units. The sale reported on this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person.</footnote>
        <footnote id="F2">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $12.95 to $12.97 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range.</footnote>
        <footnote id="F3">Represents 4,668 shares of common stock held by the Reporting Person and 40,953 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock upon vesting.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Cindy Driscoll, Attorney-in-Fact</signatureName>
        <signatureDate>2015-09-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
