-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 TDlvxXvZfZmVR9ontbUM+LevoeuYHCFvPPBqjVAWMMhPpBG9gP5yGJUzR9mF2T+B
 18x4AU7ChDvO60XIoe2fdQ==

<SEC-DOCUMENT>0001294146-10-000007.txt : 20101109
<SEC-HEADER>0001294146-10-000007.hdr.sgml : 20101109
<ACCEPTANCE-DATETIME>20101109143616
ACCESSION NUMBER:		0001294146-10-000007
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20101109
FILED AS OF DATE:		20101109
DATE AS OF CHANGE:		20101109

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ROBINSON BRUCE A
		CENTRAL INDEX KEY:			0001294146

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-18676
		FILM NUMBER:		101175734

	MAIL ADDRESS:	
		STREET 1:		900 LIGONIER STREET
		STREET 2:		PO BOX 429
		CITY:			LATROBE
		STATE:			PA
		ZIP:			15650

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			COMMERCIAL NATIONAL FINANCIAL CORP /PA
		CENTRAL INDEX KEY:			0000866054
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				251623213
		STATE OF INCORPORATION:			PA
		FISCAL YEAR END:			1207

	BUSINESS ADDRESS:	
		STREET 1:		900 LIGONIER ST
		STREET 2:		PO BOX 429
		CITY:			LATROBE
		STATE:			PA
		ZIP:			15650
		BUSINESS PHONE:		4125393501

	MAIL ADDRESS:	
		STREET 1:		900 LIGONIER ST
		STREET 2:		PO BOX 429
		CITY:			LATROBE
		STATE:			PA
		ZIP:			15650
</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>2010-11-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000866054</issuerCik>
        <issuerName>COMMERCIAL NATIONAL FINANCIAL CORP /PA</issuerName>
        <issuerTradingSymbol>CNAF</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001294146</rptOwnerCik>
            <rptOwnerName>ROBINSON BRUCE A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>900 LIGONIER STREET</rptOwnerStreet1>
            <rptOwnerStreet2>PO BOX 429</rptOwnerStreet2>
            <rptOwnerCity>LATROBE</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>15650</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, $2.00 Par Value</value>
            </securityTitle>
            <transactionDate>
                <value>2010-11-09</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>16.7</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17006.0062</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>Bruce A. Robinson</signatureName>
        <signatureDate>2010-11-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----