-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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MIC-Info: RSA-MD5,RSA,
 DJ5265zKLi+0KfYLrl8py+Rt3B6tvY1I3ZFYI8ulrt5GOXEN2XR6JkAQ6YczOfNR
 Su132T8VbBjWiG/sZp5pEQ==

<SEC-DOCUMENT>0001188839-06-000001.txt : 20060531
<SEC-HEADER>0001188839-06-000001.hdr.sgml : 20060531
<ACCEPTANCE-DATETIME>20060531183705
ACCESSION NUMBER:		0001188839-06-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20060526
FILED AS OF DATE:		20060531
DATE AS OF CHANGE:		20060531

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BANCFIRST CORP /OK/
		CENTRAL INDEX KEY:			0000760498
		STANDARD INDUSTRIAL CLASSIFICATION:	NATIONAL COMMERCIAL BANKS [6021]
		IRS NUMBER:				731221379
		STATE OF INCORPORATION:			OK
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		101 N BROADWAY STE 200
		CITY:			OKLAHOMA CITY
		STATE:			OK
		ZIP:			73102-8401
		BUSINESS PHONE:		4052701000

	MAIL ADDRESS:	
		STREET 1:		101 NORTH BROADWAY
		STREET 2:		STE 200
		CITY:			OKLAHOMA CITY
		STATE:			OK
		ZIP:			73102-8401

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	UNITED COMMUNITY CORP
		DATE OF NAME CHANGE:	19890401

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MCCALMONT J RALPH
		CENTRAL INDEX KEY:			0001188839

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-14384
		FILM NUMBER:		06878032

	BUSINESS ADDRESS:	
		STREET 1:		101 N BROADWAY
		CITY:			OKLAHOMA CITY
		STATE:			OK
		ZIP:			73102
		BUSINESS PHONE:		4052701044
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-05-26</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000760498</issuerCik>
        <issuerName>BANCFIRST CORP /OK/</issuerName>
        <issuerTradingSymbol>BANF</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001188839</rptOwnerCik>
            <rptOwnerName>MCCALMONT J RALPH</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>101 N. BROADWAY</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>OKLAHOMA CITY</rptOwnerCity>
            <rptOwnerState>OK</rptOwnerState>
            <rptOwnerZipCode>73102</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</value>
            </securityTitle>
            <transactionDate>
                <value>2006-05-26</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>45.42</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>185000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>McCalmont Family LLC</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>By Randy Foraker   For J.R. McCalmont</signatureName>
        <signatureDate>2006-05-31</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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