<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>
<periodOfReport>2003-11-21</periodOfReport>
<notSubjectToSection16>1</notSubjectToSection16>
    <issuer>
        <issuerCik>0000027096</issuerCik>
        <issuerName>DATASCOPE CORP</issuerName>
        <issuerTradingSymbol>DSCP</issuerTradingSymbol>
</issuer>
<reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001227578</rptOwnerCik>
            <rptOwnerName>PURVIN JEFFREY L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>14 PHILIPS PARKWAY</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MONTVALE</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07645</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>0</isDirector>
<isOfficer>0</isOfficer>
<isTenPercentOwner>0</isTenPercentOwner>
<isOther>1</isOther>
<officerTitle></officerTitle>
<otherText>Former VP;President of IPD</otherText>
</reportingOwnerRelationship>
</reportingOwner>
<nonDerivativeTable>
<nonDerivativeTransaction>
<securityTitle>
<value>Common Stock par value $.01 per share</value>
</securityTitle>
<transactionDate>
<value>2003-11-21</value>
</transactionDate>
<deemedExecutionDate>
</deemedExecutionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>J</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionTimeliness>
<value></value>
</transactionTimeliness>
<transactionAmounts>
<transactionShares>
<value>0.0</value>
<footnoteId id="F1"/>
</transactionShares>
<transactionPricePerShare>
<value>0.0</value>
<footnoteId id="F1"/>
</transactionPricePerShare>
<transactionAcquiredDisposedCode>
<value>A</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>1087</value>
<footnoteId id="F1"/>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</nonDerivativeTransaction>
</nonDerivativeTable>
<footnotes>
<footnote id="F1">The report is being filed to note the termination of insider status.  The reported holdings reflect the insider&#039;s beneficial ownership as of the date of termination of service.</footnote>
</footnotes>
<remarks></remarks>
<ownerSignature>
<signatureName>Jeffrey L. Purvin</signatureName>
<signatureDate>2003-11-25</signatureDate>
</ownerSignature>
</ownershipDocument>

