<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0101</schemaVersion>

    <documentType>4/A</documentType><periodOfReport>2002-05-31</periodOfReport><dateOfOriginalSubmission>2002-06-10</dateOfOriginalSubmission>
    <issuer>
        <issuerCik>0000885725</issuerCik>
        <issuerName>BOSTON SCIENTIFIC CORP</issuerName>
        <issuerTradingSymbol>BSX</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId>
            <rptOwnerCik>0000901430</rptOwnerCik>
            <rptOwnerName>ABELE JOHN E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther></reportingOwnerRelationship></reportingOwner><nonDerivativeSecurity><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2002-05-31</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>G</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>18000</value></transactionShares><transactionValue><value>0</value></transactionValue><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>26942250</value><footnoteId id="F1"/></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeSecurity><footnotes><footnote id="F1">The Reporting Person also indirectly owns 200,000 shares of common stock of the Company held by his wife and 230,719 shares of common stock of the Company held by a trust of which the Reporting Person is a trustee.</footnote></footnotes><ownerSignature><signatureName>Lawrence J. Knopf, Attorney-in-fact</signatureName><signatureDate>2003-07-02</signatureDate></ownerSignature></ownershipDocument>

