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

    <documentType>4</documentType><periodOfReport>2003-05-30</periodOfReport>
    <issuer>
        <issuerCik>0001069469</issuerCik>
        <issuerName>PRIVATE BUSINESS INC</issuerName>
        <issuerTradingSymbol>PBIZ</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId>
            <rptOwnerCik>0001229888</rptOwnerCik>
            <rptOwnerName>ONEILL BRIAN P</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>Chief Operations Officer</officerTitle></reportingOwnerRelationship></reportingOwner><derivativeSecurity><securityTitle><value>Stock Option (Option to Purchase)</value></securityTitle><conversionOrExercisePrice><value>.59</value></conversionOrExercisePrice><transactionDate><value>2003-05-30</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>40400</value></transactionShares><transactionValue><value>.59</value></transactionValue><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2003-05-30</value><footnoteId id="F1"/></exerciseDate><expirationDate><value>2013-05-30</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>40400</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>66754</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwnership></ownershipNature></derivativeSecurity><footnotes><footnote id="F1">Stock Options vest 1/4th immediately upon date of grant, and the remaining options vest 1/48th per month beginning on the first day of each month following date of grant.</footnote></footnotes><ownerSignature><signatureName>Brian P. O'Neill</signatureName><signatureDate>2003-06-02</signatureDate></ownerSignature></ownershipDocument>

