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

    <documentType>4</documentType><periodOfReport>2003-10-08</periodOfReport>
    <issuer>
        <issuerCik>0000915290</issuerCik>
        <issuerName>CONCORD COMMUNICATIONS INC</issuerName>
        <issuerTradingSymbol>CCRD</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001193594</rptOwnerCik>
            <rptOwnerName>CRUZ MELISSA H</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O CONCORD COMMUNICATIONS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>600 NICKERSON RD.</rptOwnerStreet2>
            <rptOwnerCity>MARLBORO</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01752</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>EVP, Business Services &amp; CFO</officerTitle></reportingOwnerRelationship></reportingOwner><derivativeTable><derivativeTransaction><securityTitle><value>Incentive Stock Option (right to buy)</value></securityTitle><conversionOrExercisePrice><value>14.65</value></conversionOrExercisePrice><transactionDate><value>2003-10-08</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>9038</value></transactionShares><transactionPricePerShare><value>0</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2004-10-08</value><footnoteId id="F1"/></exerciseDate><expirationDate><value>2011-10-08</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>9038</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>9038</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeTransaction><derivativeTransaction><securityTitle><value>Non-qualified Stock Options (right to buy)</value></securityTitle><conversionOrExercisePrice><value>14.65</value></conversionOrExercisePrice><transactionDate><value>2003-10-08</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>40962</value></transactionShares><transactionPricePerShare><value>0</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2004-10-08</value><footnoteId id="F1"/></exerciseDate><expirationDate><value>2011-10-08</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>40962</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>40962</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeTransaction></derivativeTable><footnotes><footnote id="F1">50,000 option shares were ganted on 10/8/03 of which 40,962 shares are Non-qualified Stock Options and 9,038 shares are Incentive Stock Options.  (A) 9,038 Incentive Stock Option shares vest as follows: 0 option shares vest and become exercisable on 10/8/04; 0 option shares vest and become exercisable on 10/8/05; 2,213 option shares vest and become exercisable on 10/8/06; and 6,825 shares vest and become exercisable on 10/8/07.  (B) 40,962 Non-qualified Stock Option Shares vest as follows:  12,500 shares vest and become exercisable on 10/8/04; 12,500 option shres vest and become exercisable on 10/8/05; 10,287 option shares vest and become exercisable on 10/8/06; and 5,675 option shares vest and become exercisable on 10/8/07.</footnote></footnotes><remarks/><ownerSignature><signatureName>Melissa H. Cruz</signatureName><signatureDate>2003-11-05</signatureDate></ownerSignature></ownershipDocument>

