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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-02-14</periodOfReport>

    <issuer>
        <issuerCik>0000077155</issuerCik>
        <issuerName>PENN TRAFFIC CO</issuerName>
        <issuerTradingSymbol>PTFC.PK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001049310</rptOwnerCik>
            <rptOwnerName>BAY HARBOUR MANAGEMENT LC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>885 THIRD AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>34TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001387025</rptOwnerCik>
            <rptOwnerName>Bay Harbour Master Ltd.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>885 THIRD AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>34TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.01</value>
            </securityTitle>
            <transactionDate>
                <value>2007-02-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>607236</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>16.75</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.01</value>
            </securityTitle>
            <transactionDate>
                <value>2007-02-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>479967</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>16.75</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1347000</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The Reporting Person acts as investment advisor to several entities and managed accounts (collectively, the &quot;Funds&quot; and individually, each a &quot;Fund&quot;) that own the shares subject to this Form 4.  As of February 16, 2007, the Funds held, in the aggregate, 1,912,992 shares of the Issuer's Common Stock (including the 1,347,000 shares reported on this Form 4 as held directly by Bay Harbour Master Ltd.), equal to approximately 23.1% of the total shares of the Issuer's Common Stock outstanding.  As investment advisor to the Funds, the Reporting Person has voting and investment control with respect to the shares held by the Funds.  The Reporting Person disclaims beneficial ownership of all shares except to the extent of any pecuniary interest therein and this filing should not be deemed an admission of beneficial ownership for Section 16 purposes or any other purpose.</footnote>
        <footnote id="F2">These shares are held by Bay Harbour Master Ltd., an investment fund for which Bay Harbour Management, L.C. acts as investment advisor.  The 479,967 shares reported as acquired by Bay Harbour Master Ltd. form part of the 607,236 shares reported on this Form 4 as acquired by Bay Harbour Management, L.C. on behalf of several funds and managed accounts it advises.  The 1,347,000 shares reported beneficially owned by Bay Harbour Master Ltd. form part of the 1,912,992 shares held by the Funds.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Kurt Cellar, Partner</signatureName>
        <signatureDate>2007-02-16</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Kurt Cellar, Partner of the Investment Manager</signatureName>
        <signatureDate>2007-02-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
