-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 HynrkaGXudb8Zx7ozqIhz1CSwE7zhdPo6/XPz9iTXcP98iqZOEDXeyf4532/Nacj
 yc5gFHvcB1mRGMNJfyz6Rw==

<SEC-DOCUMENT>0001223203-06-000030.txt : 20060210
<SEC-HEADER>0001223203-06-000030.hdr.sgml : 20060210
<ACCEPTANCE-DATETIME>20060210174032
ACCESSION NUMBER:		0001223203-06-000030
CONFORMED SUBMISSION TYPE:	5/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20051231
FILED AS OF DATE:		20060210
DATE AS OF CHANGE:		20060210

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			COALSON MAC A
		CENTRAL INDEX KEY:			0001251132

	FILING VALUES:
		FORM TYPE:		5/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-07674
		FILM NUMBER:		06600043

	MAIL ADDRESS:	
		STREET 1:		400 PINE STREET
		STREET 2:		C/O FIRST FINANCIAL BANKSHARES
		CITY:			ABILENE
		STATE:			TX
		ZIP:			79601

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FIRST FINANCIAL BANKSHARES INC
		CENTRAL INDEX KEY:			0000036029
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				750944023
		STATE OF INCORPORATION:			TX
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		400 PINE STREET
		STREET 2:		P.O. BOX 701
		CITY:			ABILENE
		STATE:			TX
		ZIP:			79601
		BUSINESS PHONE:		325.627.7167

	MAIL ADDRESS:	
		STREET 1:		P.O. BOX 701
		CITY:			ABILENE
		STATE:			TX
		ZIP:			79604
</SEC-HEADER>
<DOCUMENT>
<TYPE>5/A
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>5/A</documentType>

    <periodOfReport>2005-12-31</periodOfReport>

    <dateOfOriginalSubmission>2006-02-10</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0000036029</issuerCik>
        <issuerName>FIRST FINANCIAL BANKSHARES INC</issuerName>
        <issuerTradingSymbol>ffin</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001251132</rptOwnerCik>
            <rptOwnerName>COALSON MAC A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>400 PINE STREET</rptOwnerStreet1>
            <rptOwnerStreet2>C/O FIRST FINANCIAL BANKSHARES</rptOwnerStreet2>
            <rptOwnerCity>ABILENE</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>79601</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>2005-12-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>L</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>83</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>114428</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>common stock</value>
            </securityTitle>
            <transactionDate>
                <value>2005-12-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>L</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>73</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4382</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Spouse</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>common stock</value>
            </securityTitle>
            <transactionCoding>
                <transactionFormType></transactionFormType>
            </transactionCoding>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>107420</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The amounts above reflect shares acquired from dividend reinvestment plan at brokerage company managing these shares.</footnote>
        <footnote id="F2">This Amendment corrects a duplicate Form 5 filed in error on this date, and corrects erroneously reported amount of shares and an erroneously reported transaction date.</footnote>
        <footnote id="F3">Amount has been adjusted for four for three stock split effective June 1, 2005</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>J. Bruce Hildebrand, Attorney in Fact for Mac A. Coalson</signatureName>
        <signatureDate>2006-02-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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