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

    <documentType>4/A</documentType><periodOfReport>2003-06-30</periodOfReport><dateOfOriginalSubmission>2003-07-01</dateOfOriginalSubmission>
    <issuer>
        <issuerCik>0000746598</issuerCik>
        <issuerName>BRADY CORP</issuerName>
        <issuerTradingSymbol>BRC</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId>
            <rptOwnerCik>0001222852</rptOwnerCik>
            <rptOwnerName>OLIVER MICHAEL O</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>Senior VP - Human Resources</officerTitle></reportingOwnerRelationship></reportingOwner><derivativeSecurity><securityTitle><value>Phantom Stock Units</value></securityTitle><conversionOrExercisePrice><value>0</value><footnoteId id="F1"/></conversionOrExercisePrice><transactionDate><value>2003-06-30</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>30.3442</value></transactionShares><transactionValue><value>32.916</value></transactionValue><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>1988-08-08</value><footnoteId id="F2"/></exerciseDate><expirationDate><value>1988-08-08</value><footnoteId id="F2"/></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Class A Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>30.3442</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>5485.1622</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwnership></ownershipNature></derivativeSecurity><footnotes><footnote id="F1">This security converts to a common stock on a 1 for 1 basis</footnote><footnote id="F2">The phantom stock units were accured under the Brady Corporation employee deferred compensation agreement and are to be settled in installment payments of Brady's Class A Common Stock upon the person's cessation of services as an employee. </footnote></footnotes><ownerSignature><signatureName>/s/ Donald E. Rearic</signatureName><signatureDate>2003-07-08</signatureDate></ownerSignature></ownershipDocument>

