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

    <documentType>4/A</documentType>
<periodOfReport>2003-11-06</periodOfReport>
<dateOfOriginalSubmission>2003-11-07</dateOfOriginalSubmission>
<notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000027096</issuerCik>
        <issuerName>DATASCOPE CORP</issuerName>
        <issuerTradingSymbol>DSCP</issuerTradingSymbol>
</issuer>
<reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001227580</rptOwnerCik>
            <rptOwnerName>SOUTHARD DONALD J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O DATASCOPE CORP.</rptOwnerStreet1>
            <rptOwnerStreet2>14 PHILIPS PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>MONTVALE,</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07645</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>0</isDirector>
<isOfficer>1</isOfficer>
<isTenPercentOwner>0</isTenPercentOwner>
<isOther>0</isOther>
<officerTitle>VP; President, PM Division</officerTitle>
<otherText></otherText>
</reportingOwnerRelationship>
</reportingOwner>
<nonDerivativeTable>
<nonDerivativeTransaction>
<securityTitle>
<value>Common Stock par value $.01 per share</value>
</securityTitle>
<transactionDate>
<value>2003-11-06</value>
<footnoteId id="F3"/>
</transactionDate>
<deemedExecutionDate>
</deemedExecutionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>M</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionTimeliness>
<value></value>
</transactionTimeliness>
<transactionAmounts>
<transactionShares>
<value>7500</value>
</transactionShares>
<transactionPricePerShare>
<value>24.688</value>
</transactionPricePerShare>
<transactionAcquiredDisposedCode>
<value>A</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>7500</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</nonDerivativeTransaction>
<nonDerivativeTransaction>
<securityTitle>
<value>Common Stock par value $.01 per share</value>
</securityTitle>
<transactionDate>
<value>2003-11-06</value>
</transactionDate>
<deemedExecutionDate>
</deemedExecutionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>S</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionTimeliness>
<value></value>
</transactionTimeliness>
<transactionAmounts>
<transactionShares>
<value>7500</value>
</transactionShares>
<transactionPricePerShare>
<value>34.59</value>
</transactionPricePerShare>
<transactionAcquiredDisposedCode>
<value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>0</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</nonDerivativeTransaction>
<nonDerivativeTransaction>
<securityTitle>
<value>Common Stock , par value $.01 per share</value>
</securityTitle>
<transactionDate>
<value>2003-06-30</value>
<footnoteId id="F1"/>
</transactionDate>
<deemedExecutionDate>
</deemedExecutionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>J</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionTimeliness>
<value></value>
</transactionTimeliness>
<transactionAmounts>
<transactionShares>
<value>78</value>
</transactionShares>
<transactionPricePerShare>
<footnoteId id="F1"/>
</transactionPricePerShare>
<transactionAcquiredDisposedCode>
<value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>0</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</nonDerivativeTransaction>
<nonDerivativeTransaction>
<securityTitle>
<value>Common Stock par value $.01 per share</value>
</securityTitle>
<transactionDate>
<value>2003-11-06</value>
</transactionDate>
<deemedExecutionDate>
</deemedExecutionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>M</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionTimeliness>
<value></value>
</transactionTimeliness>
<transactionAmounts>
<transactionShares>
<value>3250</value>
</transactionShares>
<transactionPricePerShare>
<value>26.938</value>
</transactionPricePerShare>
<transactionAcquiredDisposedCode>
<value>A</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>3250</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</nonDerivativeTransaction>
<nonDerivativeTransaction>
<securityTitle>
<value>Common Stock par value $.01 per share</value>
</securityTitle>
<transactionDate>
<value>2003-11-06</value>
</transactionDate>
<deemedExecutionDate>
</deemedExecutionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>S</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionTimeliness>
<value></value>
</transactionTimeliness>
<transactionAmounts>
<transactionShares>
<value>3250</value>
</transactionShares>
<transactionPricePerShare>
<value>34.59</value>
</transactionPricePerShare>
<transactionAcquiredDisposedCode>
<value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>0</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</nonDerivativeTransaction>
</nonDerivativeTable>
<derivativeTable>
<derivativeTransaction>
<securityTitle>
<value>Exercise of Stock Option (right to buy)</value>
</securityTitle>
<conversionOrExercisePrice>
<value>24.688</value>
</conversionOrExercisePrice>
<transactionDate>
<value>2003-11-06</value>
</transactionDate>
<deemedExecutionDate>
</deemedExecutionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>M</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionTimeliness>
<value></value>
</transactionTimeliness>
<transactionAmounts>
<transactionShares>
<value>7500</value>
</transactionShares>
<transactionPricePerShare>
<footnoteId id="F2"/>
</transactionPricePerShare>
<transactionAcquiredDisposedCode>
<value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<exerciseDate>
<value>2000-02-24</value>
</exerciseDate>
<expirationDate>
<value>2008-02-23</value>
</expirationDate>
<underlyingSecurity>
<underlyingSecurityTitle>
<value>Common Stock</value>
</underlyingSecurityTitle>
<underlyingSecurityShares>
<value>7500</value>
</underlyingSecurityShares>
</underlyingSecurity>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>0</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</derivativeTransaction>
<derivativeTransaction>
<securityTitle>
<value>Exercise of Stock Option (right to buy)</value>
</securityTitle>
<conversionOrExercisePrice>
<value>26.938</value>
</conversionOrExercisePrice>
<transactionDate>
<value>2003-11-06</value>
</transactionDate>
<deemedExecutionDate>
</deemedExecutionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>M</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionTimeliness>
<value></value>
</transactionTimeliness>
<transactionAmounts>
<transactionShares>
<value>3250</value>
</transactionShares>
<transactionPricePerShare>
<footnoteId id="F2"/>
</transactionPricePerShare>
<transactionAcquiredDisposedCode>
<value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<exerciseDate>
<value>2002-05-26</value>
</exerciseDate>
<expirationDate>
<value>2009-05-25</value>
</expirationDate>
<underlyingSecurity>
<underlyingSecurityTitle>
<value>Common Stock</value>
</underlyingSecurityTitle>
<underlyingSecurityShares>
<value>3250</value>
</underlyingSecurityShares>
</underlyingSecurity>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>0</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</derivativeTransaction>
</derivativeTable>
<footnotes>
<footnote id="F1">These shares were disposed of during the fiscal year pursuant to the Datascope Corp. 401(k) Savings and Supplemental Retirement Plan at prices ranging from $21.91 to $32.31.</footnote>
<footnote id="F2">See column 2 for exercise price</footnote>
<footnote id="F3">This Amendment is being filed to correct references to the 10/6/03 transaction date to 11/6/03 and the omission of the line items in Table II</footnote>
</footnotes>
<remarks></remarks>
<ownerSignature>
<signatureName>Donald J. Southard</signatureName>
<signatureDate>2003-11-17</signatureDate>
</ownerSignature>
</ownershipDocument>

