-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 Q2UuG5lp0oQllTlpWoHF21wgCb89fFwQRnQh+xgAy69FbGGKibuCCsoYPf96S/m2
 HDWOP3H1fnDiW/isEjFFOg==

<SEC-DOCUMENT>0000003982-09-000039.txt : 20091001
<SEC-HEADER>0000003982-09-000039.hdr.sgml : 20091001
<ACCEPTANCE-DATETIME>20091001173807
ACCESSION NUMBER:		0000003982-09-000039
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090930
FILED AS OF DATE:		20091001
DATE AS OF CHANGE:		20091001

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HIDAYATALLAH MUNAWAR H
		CENTRAL INDEX KEY:			0001140824

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-02199
		FILM NUMBER:		091099661

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Allis Chalmers Energy Inc.
		CENTRAL INDEX KEY:			0000003982
		STANDARD INDUSTRIAL CLASSIFICATION:	OIL, GAS FIELD SERVICES, NBC [1389]
		IRS NUMBER:				390126090
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		5075 WESTHEIMER
		STREET 2:		SUITE 890
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77056
		BUSINESS PHONE:		713-369-0550

	MAIL ADDRESS:	
		STREET 1:		5075 WESTHEIMER
		STREET 2:		SUITE 890
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77056

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ALLIS CHALMERS CORP
		DATE OF NAME CHANGE:	19920703

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ALLIS CHALMERS MANUFACTURING CO
		DATE OF NAME CHANGE:	19710614
</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>2009-09-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000003982</issuerCik>
        <issuerName>Allis Chalmers Energy Inc.</issuerName>
        <issuerTradingSymbol>ALY</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001140824</rptOwnerCik>
            <rptOwnerName>HIDAYATALLAH MUNAWAR H</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5075 WESTHEIMER, SUITE 890</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77056</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman and CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-09-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.3052</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>50226</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Hidayatallah Family Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Munawar Hidayatallah SEP IRA</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The Reporting Person sold these shares solely to satisfy certain personal tax obligations.</footnote>
        <footnote id="F2">Represents the average price of the Reporting Person's disposition of 10,000 shares in four separate transactions ranging from $4.29 to $4.32 per share.  The Issuer undertakes to provide upon request by the SEC staff, or a security holder of the Issuer, full information regarding the number of shares purchased or sold at each separate price.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Theodore F. Pound III through POA</signatureName>
        <signatureDate>2009-10-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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