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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-02-26</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000884719</issuerCik>
        <issuerName>FOCUS ENHANCEMENTS INC</issuerName>
        <issuerTradingSymbol>FCSE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001250879</rptOwnerCik>
            <rptOwnerName>WILLIAMS GARY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O FOCUS ENHANCEMENTS INC</rptOwnerStreet1>
            <rptOwnerStreet2>1370 DELL AVE</rptOwnerStreet2>
            <rptOwnerCity>CAMPBELL</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95008</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP of Finance &amp; CFO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-02-26</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>3129</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.44</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>104482</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <remarks>On February 24, 2007, 8,750 shares of common stock vested in accordance with an original restricted stock grant dated February 24, 2005. As February 24, 2007 was a Saturday, the next business day (2/26/2007) was used to determine the fair market value of the shares. Filer has chosen to satisfy the tax withholding obligation by having the Company withhold shares equal to the amount of the tax obligation. Such withholding of shares is reported as a disposition using code F.</remarks>

    <ownerSignature>
        <signatureName>/s/ Gary Williams</signatureName>
        <signatureDate>2007-02-28</signatureDate>
    </ownerSignature>
</ownershipDocument>
