<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-06-18</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000844143</issuerCik>
        <issuerName>JOE'S JEANS INC.</issuerName>
        <issuerTradingSymbol>JOEZ</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001410854</rptOwnerCik>
            <rptOwnerName>Sandhu Hamish</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5901 S EASTERN AVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>COMMERCE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90040</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Executive Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-06-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4213</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.2</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>103887</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">On December 18, 2007,Mr.Sandhu received a grant of 100,000 shares of Restricted Stock Units (&quot;RSU&quot;) that represented a contingent right to recieve one share of the Company's Common Stock.  The RSUs were granted pursuant to the 2004 Stock Incentive Plan and previously reported as acquired on Table I on a Form 4 dated December 18, 2007.  On June 18, 2008 in accordance with the terms of the RSU agreement, 1/8 of those shares vested and the Company withheld an equivalent amount of RSUs at fair market value to pay the minimum tax withholding requirements for Mr. Sandhu.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Hamish Sandhu</signatureName>
        <signatureDate>2008-06-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
