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

    <schemaVersion>X0203</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2010-08-20</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001164552</issuerCik>
        <issuerName>CDSS Wind Down Inc</issuerName>
        <issuerTradingSymbol>CWDW</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001497177</rptOwnerCik>
            <rptOwnerName>GEM Lighting, L.L.C.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O GREEN ENERGY MANAGEMENT SERVICES INC</rptOwnerStreet1>
            <rptOwnerStreet2>381 TEANECK ROAD</rptOwnerStreet2>
            <rptOwnerCity>TEANECK</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07666</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, $0.0001 par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>65623216</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">All of the shares owned by the Reporting Person are beneficially owned by each of Deborah Samuel, the wife of Michael Samuel, the Issuer's Chairman, President, Chief Executive Officer and Director, and Jonathan Samuel, Mr. Samuel's son.  Ms. Samuel and Jonathan Samuel are the sole members of the Reporting Person. Michael Samuel does not have direct beneficial ownership of any of the Issuer's common stock.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Robert Weinstein, as attorney-in-fact for GEM Lighting, L.L.C.</signatureName>
        <signatureDate>2010-08-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
