<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-12-31</periodOfReport>

    <issuer>
        <issuerCik>0001000623</issuerCik>
        <issuerName>SCHWEITZER MAUDUIT INTERNATIONAL INC</issuerName>
        <issuerTradingSymbol>SWM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001026161</rptOwnerCik>
            <rptOwnerName>ARNOLD CLAIRE L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SCHWEITZER-MAUDUIT INTERNAT'L, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>100 NORTH POINT CENTER EAST, SUITE 600</rptOwnerStreet2>
            <rptOwnerCity>ALPHARETTA, GA</rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode>30022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>SWMCommon Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4210</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock Units</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2008-12-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>91.5814</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>20.02</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>1988-08-08</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>1988-08-08</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>91.5814</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>12314.6536</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Dividends credited pursuant to the Director's election in accordance with the Schweitzer-Mauduit International, Inc. Deferred Compensation Plan for Non-Employee Directors and the Schweitzer-Mauduit International, Inc. Deferred Compensation Plan No. 2 for Non-Employee Directors (&quot;Plans&quot;).  The Plans were filed as Exhibit 10.8.2 to the first quarter 2000 10-Q and Exhibit 10.15 to the 2004 10-K, respectively.</footnote>
        <footnote id="F2">Stock Units can be converted to cash or SWM common stock upon the earlier of retirement from the Board or termination as a Director in accordance with the Plan.   Conversion into shares or cash is based on the fair market value of SWM common stock on the date of conversion.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Honor Winks as Attorney-in-fact for Claire L. Arnold</signatureName>
        <signatureDate>2009-01-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
