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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-01-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001211582</rptOwnerCik>
            <rptOwnerName>LEFRAK RICHARD S</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O LEFRAK ORGANIZATION INC</rptOwnerStreet1>
            <rptOwnerStreet2>40 WEST 57TH STREET, 23RD FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2006-01-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>543</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>69.05</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8392</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These shares are issued to Mr. LeFrak pursuant to the Sequa Corporation 1998 Directors' Stock Compensation Plan (the &quot;Plan&quot;).  The shares are restricted from disposition or transfer in accordance with the provisions set forth in the Plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/Diane C. Bunt, as attorney-in-fact</signatureName>
        <signatureDate>2006-01-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0202
4
2006-01-01
0
0000095301
SEQUA CORP /DE/
SQAA
0001211582
LEFRAK RICHARD S
C/O LEFRAK ORGANIZATION INC
40 WEST 57TH STREET, 23RD FLOOR
NEW YORK
NY
10019
1
0
0
0
Class A Common Stock
2006-01-01
4
A
0
543
69.05
A
8392
D
These shares are issued to Mr. LeFrak pursuant to the Sequa Corporation 1998 Directors' Stock Compensation Plan (the "Plan").  The shares are restricted from disposition or transfer in accordance with the provisions set forth in the Plan.
/s/Diane C. Bunt, as attorney-in-fact
2006-01-04