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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-10-07</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000909109</issuerCik>
        <issuerName>PHILADELPHIA CONSOLIDATED HOLDING CORP</issuerName>
        <issuerTradingSymbol>PHLY</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000937439</rptOwnerCik>
            <rptOwnerName>MAGUIRE JAMES J ET AL</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>SUITE 100</rptOwnerStreet1>
            <rptOwnerStreet2>ONE BALA PLAZA</rptOwnerStreet2>
            <rptOwnerCity>BALA CYNWYD</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>19004</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman of the BOD</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock (no par value)</value>
            </securityTitle>
            <transactionDate>
                <value>2004-10-07</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value>E</value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>771128</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2025394</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnotes</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock (no par value)</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2380415</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F4"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Effective as of October 7, 2004, Ms. Frances M. Maguire, Mr. James J. Maguire's wife, has been named as co-trustee of a number of family trusts which hold an aggregate of 771,128 shares of the Company's stock and of which her children are the beneficiaries.  Mr. Maguire claims beneficial ownership of these shares and the filing of this report is not an admission that he is a beneficial owner of these shares for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.</footnote>
        <footnote id="F2">Not Applicable</footnote>
        <footnote id="F3">Of these shares:  800,000 shares are held by a trust of which Ms. Frances M. Maguire, Mr. James J. Maguire's wife, is the trustee and Mr. James J. Maguire is the beneficiary; 771,128 shares are held in family trusts of which Mr. Maguire's wife is co-trustee; 258,266 shares are owned by the Maguire Foundation, of which Mr. Maguire is co-director with his wife, and 196,000 shares are owned of record by Mr. Maguire's wife.  Mr. Maguire disclaims beneficial ownership of these 2,025,394 shares and the filing of this report is not an admission that he is a beneficial owner of these shares for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.</footnote>
        <footnote id="F4">Of these shares, 1,750,500 are owned jointly by Mr. Maguire and his wife, Frances M. Maguire.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Craig P. Keller, Attorney-In-Fact</signatureName>
        <signatureDate>2004-10-08</signatureDate>
    </ownerSignature>
</ownershipDocument>

