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

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-08-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000912908</issuerCik>
        <issuerName>FOAMEX INTERNATIONAL INC</issuerName>
        <issuerTradingSymbol>FMXL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001263972</rptOwnerCik>
            <rptOwnerName>D. E. SHAW LAMINAR PORTFOLIOS, L.L.C.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>120 WEST FORTY-FIFTH STREET</rptOwnerStreet1>
            <rptOwnerStreet2>39TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10036</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See footnotes 1 and 2.</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001009268</rptOwnerCik>
            <rptOwnerName>D. E. SHAW &amp; CO, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>120 WEST FORTY-FIFTH STREET</rptOwnerStreet1>
            <rptOwnerStreet2>39TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10036</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See footnotes 1 and 2.</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001277502</rptOwnerCik>
            <rptOwnerName>D. E. SHAW &amp; CO, L.L.C.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>120 WEST FORTY-FIFTH STREET</rptOwnerStreet1>
            <rptOwnerStreet2>39TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10036</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See footnotes 1 and 2.</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001023870</rptOwnerCik>
            <rptOwnerName>SHAW DAVID E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>120 WEST FORTY-FIFTH STREET</rptOwnerStreet1>
            <rptOwnerStreet2>39TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10036</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See footnotes 1 and 2.</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-08-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>10938397</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.65</value>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>176484109</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">D. E. Shaw &amp; Co., L.P. (&quot;DESCO LP&quot;), as investment adviser to D. E. Shaw Laminar Portfolios, L.L.C. (&quot;Laminar&quot;); D. E. Shaw &amp; Co., L.L.C. (&quot;DESCO LLC&quot;), as managing member of Laminar; and David E. Shaw (as president and sole shareholder of D. E. Shaw &amp; Co., Inc., which is the general partner of DESCO LP, and as president and sole shareholder of D. E. Shaw &amp; Co. II, Inc., which is the managing member of DESCO LLC) may be deemed to be the beneficial owners of more than 10% of the Common Stock of the Issuer for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934.</footnote>
        <footnote id="F2">(Continued from Footnote 1) In accordance with instruction 4(b)(iv), the entire amount of securities of the Issuer that may be deemed to be beneficially owned by DESCO LP, DESCO LLC, or Laminar is reported herein. Each of DESCO LP, DESCO LLC, and David E. Shaw disclaims any beneficial ownership of any of the securities listed in this Form 4, except to the extent of any pecuniary interest therein. The reporting persons also may be deemed, for Section 16 purposes, directors of the Issuer by virtue of each of DESCO LP employees Seth Charnow's and David Lyon's service as a member of the Issuer's board of directors. None of Laminar, DESCO LP, DESCO LLC, or David E. Shaw serves as a director of the Issuer.</footnote>
        <footnote id="F3">Laminar acquired 10,938,397 shares of Common Stock in the second lien term loan offering conducted by the Issuer pursuant to the Equity Commitment Agreement, dated April 1, 2008, among the Issuer and Laminar, Sigma Capital Associates, LLC, CGDO, LLC (as agent on behalf of Chilton Global Distressed Opportunities Master Fund, L.P.), and Q Funding III, L.P.</footnote>
        <footnote id="F4">Pursuant to the terms of the second lien term loan offering, Laminar paid the purchase price by assigning to the Issuer, on a dollar-for-dollar basis at par, loans outstanding under the Second Lien Term Credit Agreement, dated as of February 12, 2007, by and among Foamex L.P., the Issuer, Bank of America, N.A., as Administrative Agent and Collateral Agent, and the lenders and other parties named therein, in an aggregate par value of $7,109,958.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>D. E. Shaw Laminar Portfolios, L.L.C. By: D. E. Shaw &amp; Co. L.L.C., as managing member By: /s/ Rochelle Elias, Chief Compliance Officer</signatureName>
        <signatureDate>2008-08-19</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>D. E. Shaw &amp; Co., L.P. By: /s/ Rochelle Elias, Chief Compliance Officer</signatureName>
        <signatureDate>2008-08-19</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>D. E. Shaw &amp; Co., L.L.C. By: /s/ Rochelle Elias, Chief Compliance Officer</signatureName>
        <signatureDate>2008-08-19</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>David E. Shaw By: /s/ Rochelle Elias, Attorney-in-Fact for David E. Shaw</signatureName>
        <signatureDate>2008-08-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
