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

    <documentType>4</documentType><periodOfReport>2004-01-21</periodOfReport>
    <issuer>
        <issuerCik>0000888693</issuerCik>
        <issuerName>ISCO INTERNATIONAL INC</issuerName>
        <issuerTradingSymbol>ISO</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001267497</rptOwnerCik>
            <rptOwnerName>CESARIO FRANK</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>451 KINGSTON COURT</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MT. PROSPECT</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60056</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>Chief Financial Officer</officerTitle></reportingOwnerRelationship></reportingOwner><derivativeTable><derivativeTransaction><securityTitle><value>Stock Option (right to buy)</value></securityTitle><conversionOrExercisePrice><value>.14</value></conversionOrExercisePrice><transactionDate><value>2004-01-21</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>400000</value></transactionShares><transactionPricePerShare><footnoteId id="F2"/></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><footnoteId id="F1"/></exerciseDate><expirationDate><value>2014-01-21</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>400000</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>400000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeTransaction></derivativeTable><footnotes><footnote id="F1">The option vests ratably on a monthly basis over a two year period from the date of grant.</footnote><footnote id="F2">This an option grant for which there was no purchase price.</footnote></footnotes><remarks/><ownerSignature><signatureName>Frank Cesario</signatureName><signatureDate>2004-01-22</signatureDate></ownerSignature></ownershipDocument>

