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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001229952-09-000016.txt : 20090522
<SEC-HEADER>0001229952-09-000016.hdr.sgml : 20090522
<ACCEPTANCE-DATETIME>20090518154349
ACCESSION NUMBER:		0001229952-09-000016
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090518
FILED AS OF DATE:		20090518
DATE AS OF CHANGE:		20090518

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DOLAN JOHN J
		CENTRAL INDEX KEY:			0001229968

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-11138
		FILM NUMBER:		09836657

	MAIL ADDRESS:	
		STREET 1:		22 N 6TH ST
		CITY:			INDIANA
		STATE:			PA
		ZIP:			15701

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FIRST COMMONWEALTH FINANCIAL CORP /PA/
		CENTRAL INDEX KEY:			0000712537
		STANDARD INDUSTRIAL CLASSIFICATION:	NATIONAL COMMERCIAL BANKS [6021]
		IRS NUMBER:				251428528
		STATE OF INCORPORATION:			PA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		OLD COURTHOUSE SQUARE
		STREET 2:		22 N SIXTH ST
		CITY:			INDIANA
		STATE:			PA
		ZIP:			15701
		BUSINESS PHONE:		7243497220

	MAIL ADDRESS:	
		STREET 1:		22 NORTH SIXTH STREET
		STREET 2:		P.O. BOX 400
		CITY:			INDIANA
		STATE:			PA
		ZIP:			15701
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-05-18</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000712537</issuerCik>
        <issuerName>FIRST COMMONWEALTH FINANCIAL CORP /PA/</issuerName>
        <issuerTradingSymbol>fcf</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001229968</rptOwnerCik>
            <rptOwnerName>DOLAN JOHN J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>22 N 6TH ST</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>INDIANA</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>15701</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President &amp; CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-05-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>8.18</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>46806</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>12.06</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2003-12-31</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-01-13</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>16347</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>16347</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Incentive/nonqualified stock option grant--option to buy</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Wendy Reynolds, POA, for John J. Dolan</signatureName>
        <signatureDate>2009-05-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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