-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 N+h1nco3C9Y+Y/xXfuMuf4yEzk5V56ZAEZ+GMhraDtVGsVp/tn27dNHWeOqXgLF3
 DYPTQHJsO5MY81UgWDVoTw==

<SEC-DOCUMENT>0001179110-09-013715.txt : 20090925
<SEC-HEADER>0001179110-09-013715.hdr.sgml : 20090925
<ACCEPTANCE-DATETIME>20090925154728
ACCESSION NUMBER:		0001179110-09-013715
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080828
FILED AS OF DATE:		20090925
DATE AS OF CHANGE:		20090925

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LACOMBE DONALD G
		CENTRAL INDEX KEY:			0001185168

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08182
		FILM NUMBER:		091087606

	MAIL ADDRESS:	
		STREET 1:		1303 MIDNIGHT DRIVE
		CITY:			SAN ANTONIO
		STATE:			TX
		ZIP:			78258

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PIONEER DRILLING CO
		CENTRAL INDEX KEY:			0000320575
		STANDARD INDUSTRIAL CLASSIFICATION:	DRILLING OIL & GAS WELLS [1381]
		IRS NUMBER:				742088619
		STATE OF INCORPORATION:			TX
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1250 N.E. LOOP 410
		STREET 2:		SUITE 1000
		CITY:			SAN ANTONIO
		STATE:			TX
		ZIP:			78209
		BUSINESS PHONE:		5128287689

	MAIL ADDRESS:	
		STREET 1:		1250 N.E. LOOP 410
		STREET 2:		SUITE 1000
		CITY:			SAN ANTONIO
		STATE:			TX
		ZIP:			78209

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SOUTH TEXAS DRILLING & EXPLORATION INC
		DATE OF NAME CHANGE:	19920703

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SOUTH TEXAS DRILLING CO
		DATE OF NAME CHANGE:	19810715
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4/A -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2008-08-28</periodOfReport>

    <dateOfOriginalSubmission>2008-09-02</dateOfOriginalSubmission>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0000320575</issuerCik>
        <issuerName>PIONEER DRILLING CO</issuerName>
        <issuerTradingSymbol>PDC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001185168</rptOwnerCik>
            <rptOwnerName>LACOMBE DONALD G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1250 N E LOOP 410 #1000</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN ANTONIO</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>78209</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP, Pioneer Drilling Services</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-08-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3900</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3900</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents a restricted stock award of 3,900 shares that was previously reported on Table II of a Form 4 filed by the reporting person on September 2, 2008.  This restricted stock award vests in three equal annual installments, with the first 1/3 shares vesting on August 28, 2009.</footnote>
        <footnote id="F2">Reflects the amount of common stock beneficially owned by the reporting person on August 28, 2008.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Donald G. Lacombe</signatureName>
        <signatureDate>2009-09-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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