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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-12-03</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000095301</issuerCik>
        <issuerName>SEQUA CORP /DE/</issuerName>
        <issuerTradingSymbol>SQAA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001220625</rptOwnerCik>
            <rptOwnerName>ELLIS ROBERT F</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1></rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity></rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Senior Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee stock option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>41.7</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-12-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>133.3</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2008-09-25</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>4000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The option, which provided vesting in 3 equal annual installments beginning 09/25/2004, was cancelled pursuant to Agreement and Plan of Merger, dated as of July 8, 2007, by and among Blue Jay Acquisition Corporation, Blue Jay Merger Corporation and Sequa Corporation (the &quot;Merger Agreement&quot;) in exchange for a cash payment representing the difference between the exercise price of the option and the exchange price of the stock under the Merger Agreement of $175 per share.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/Robert F. Ellis</signatureName>
        <signatureDate>2007-12-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0202
4
2007-12-03
0
0000095301
SEQUA CORP /DE/
SQAA
0001220625
ELLIS ROBERT F
0
1
0
0
Senior Vice President
Employee stock option (right to buy)
41.7
2007-12-03
4
D
0
4000
133.3
D
2008-09-25
Class A Common Stock
4000
0
D
The option, which provided vesting in 3 equal annual installments beginning 09/25/2004, was cancelled pursuant to Agreement and Plan of Merger, dated as of July 8, 2007, by and among Blue Jay Acquisition Corporation, Blue Jay Merger Corporation and Sequa Corporation (the "Merger Agreement") in exchange for a cash payment representing the difference between the exercise price of the option and the exchange price of the stock under the Merger Agreement of $175 per share.
/s/Robert F. Ellis
2007-12-04