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

    <documentType>4</documentType><periodOfReport>2004-01-21</periodOfReport>
    <issuer>
        <issuerCik>0000200406</issuerCik>
        <issuerName>JOHNSON &amp; JOHNSON</issuerName>
        <issuerTradingSymbol>JNJ</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001189009</rptOwnerCik>
            <rptOwnerName>LENEHAN JAMES T</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>JOHNSON &amp; JOHNSON</rptOwnerStreet1>
            <rptOwnerStreet2>ONE JOHNSON &amp; JOHNSON PLAZA</rptOwnerStreet2>
            <rptOwnerCity>NEW BRUNSWICK</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>08933</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>Vice Chairman</officerTitle></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common</value></securityTitle><transactionDate><value>2004-01-21</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>M</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>230800</value></transactionShares><transactionPricePerShare><value>13.41</value><footnoteId id="F1"/></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>430172</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>Common</value></securityTitle><transactionDate><value>2004-01-21</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>S</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>15700</value></transactionShares><transactionPricePerShare><value>51.64</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>414472</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>Common</value></securityTitle><transactionDate><value>2004-01-21</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>S</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>37600</value></transactionShares><transactionPricePerShare><value>51.62</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>376872</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>Common</value></securityTitle><transactionDate><value>2004-01-21</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>S</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>177500</value></transactionShares><transactionPricePerShare><value>51.60</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>199372</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeHolding><securityTitle><value>Common</value><footnoteId id="F2"/></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>8509</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>401 (k) and ESOP Savings Plans</value></natureOfOwnership></ownershipNature></nonDerivativeHolding><nonDerivativeHolding><securityTitle><value>Common</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>1475</value><footnoteId id="F3"/></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>In Custody for Son</value></natureOfOwnership></ownershipNature></nonDerivativeHolding></nonDerivativeTable><derivativeTable><derivativeHolding><securityTitle><value>Phantom Stock Units</value></securityTitle><conversionOrExercisePrice><value>0</value><footnoteId id="F4"/></conversionOrExercisePrice><exerciseDate><footnoteId id="F5"/></exerciseDate><expirationDate><footnoteId id="F5"/></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common</value></underlyingSecurityTitle><underlyingSecurityShares><footnoteId id="F5"/></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>13926</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding><derivativeTransaction><securityTitle><value>Employee Stock Option (Right to Buy)</value><footnoteId id="F6"/></securityTitle><conversionOrExercisePrice><value>13.41</value><footnoteId id="F1"/></conversionOrExercisePrice><transactionDate><value>2004-01-21</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>M</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>230800</value></transactionShares><transactionPricePerShare><value>13.41</value><footnoteId id="F1"/></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>1996-12-01</value></exerciseDate><expirationDate><value>2004-12-01</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common</value></underlyingSecurityTitle><underlyingSecurityShares><value>230800</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>0</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeTransaction></derivativeTable><footnotes><footnote id="F1">Adjusted to reflect two-for-one stock splits in 1996 and 2001.</footnote><footnote id="F2">Shares held under Johnson &amp; Johnson's 401(k) and ESOP Savings Plans as of 12/31/2003.</footnote><footnote id="F3">Held in custody for son.  The reporting person disclaims beneficial ownership of these securities, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.</footnote><footnote id="F4">The Phantom Stock converts into common stock on a one-for-one basis.</footnote><footnote id="F5">The Phantom Stock Units held under the Issuer's Executive Income Deferral Plan as of December 31, 2003  are to be settled in cash upon the Reporting Person's Retirement.</footnote><footnote id="F6">Awarded under Issuer's Stock Option Plan and exercisable in increments of 20% per year  starting two years from date of grant.</footnote></footnotes><remarks/><ownerSignature><signatureName>M. H. Ullmann attorney-in-fact for J. T. Lenehan</signatureName><signatureDate>2004-01-21</signatureDate></ownerSignature></ownershipDocument>

