-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 CafWxfoPG9i/VweX2GOBBMZrkyj5M2cHFUcZLExKebJBaPj65qEAvjzh2bPbGJ+V
 k/IRC6apRpxTVAmxowRLBQ==

<SEC-DOCUMENT>0000895126-04-000129.txt : 20040817
<SEC-HEADER>0000895126-04-000129.hdr.sgml : 20040817
<ACCEPTANCE-DATETIME>20040817180613
ACCESSION NUMBER:		0000895126-04-000129
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040811
FILED AS OF DATE:		20040817

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:			0331

	BUSINESS ADDRESS:	
		STREET 1:		9310 BROADWAY BLDG I
		CITY:			SAN ANTONIO
		STATE:			TX
		ZIP:			78217
		BUSINESS PHONE:		5128287689

	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

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CHESAPEAKE ENERGY CORP
		CENTRAL INDEX KEY:			0000895126
		STANDARD INDUSTRIAL CLASSIFICATION:	CRUDE PETROLEUM & NATURAL GAS [1311]
		STATE OF INCORPORATION:			OK
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08182
		FILM NUMBER:		04982805

	BUSINESS ADDRESS:	
		STREET 1:		6100 N WESTERN AVE
		CITY:			OKLAHOMA CITY
		STATE:			OK
		ZIP:			73118
		BUSINESS PHONE:		4058488000

	MAIL ADDRESS:	
		STREET 1:		6100 NORTH WESTERN AVE
		CITY:			OKLAHOMA CITY
		STATE:			OK
		ZIP:			73118
</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>2004-08-11</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000895126</rptOwnerCik>
            <rptOwnerName>CHESAPEAKE ENERGY CORP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>6100 NORTH WESTERN AVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>OKLAHOMA CITY</rptOwnerCity>
            <rptOwnerState>OK</rptOwnerState>
            <rptOwnerZipCode>73118</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-08-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>631133</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.9</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5964466</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-08-16</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>477000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>7.25</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6441466</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>Jennifer M. Grigsby</signatureName>
        <signatureDate>2004-08-17</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----