-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001209839-03-000002.txt : 20030520
<SEC-HEADER>0001209839-03-000002.hdr.sgml : 20030520
<ACCEPTANCE-DATETIME>20030519213056
ACCESSION NUMBER:		0001209839-03-000002
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030509
FILED AS OF DATE:		20030520

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			KANOFSKY GORDON
		CENTRAL INDEX KEY:			0001209839

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-22494
		FILM NUMBER:		03711327

	BUSINESS ADDRESS:	
		STREET 1:		AMERISTAR COSINOS
		STREET 2:		3773 HOWARD HUGHES PKWY SUITE 490 S
		CITY:			LAS VAGAS
		STATE:			NV
		ZIP:			89109
		BUSINESS PHONE:		7025677000

	MAIL ADDRESS:	
		STREET 1:		AMERISTAR CASINOS
		STREET 2:		3773 HOWARD HUGHES SUITE 490 S
		CITY:			LAS VAGAS
		STATE:			NV
		ZIP:			89109

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			AMERISTAR CASINOS INC
		CENTRAL INDEX KEY:			0000912145
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-MISCELLANEOUS AMUSEMENT & RECREATION [7990]
		IRS NUMBER:				880304799
		STATE OF INCORPORATION:			NV
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		3773 HOWARD HUGHES PKWY
		STREET 2:		SUITE 490 SOUTH
		CITY:			LAS VEGAS
		STATE:			NV
		ZIP:			89109
		BUSINESS PHONE:		7025677000

	MAIL ADDRESS:	
		STREET 1:		3773 HOWARD HUGHES PKWY
		STREET 2:		SUITE 490 SOUTH
		CITY:			LAS VEGAS
		STATE:			NV
		ZIP:			89109
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <documentType>4/A</documentType>

    <periodOfReport>2003-05-09</periodOfReport>

    <dateOfOriginalSubmission>2003-05-12</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000912145</issuerCik>
        <issuerName>AMERISTAR CASINOS INC</issuerName>
        <issuerTradingSymbol>ASCA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001209839</rptOwnerCik>
            <rptOwnerName>KANOFSKY GORDON</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Executive Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>Common Stock</value>
        </securityTitle>
        <transactionDate>
            <value>2003-05-09</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>M</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>26600</value>
            </transactionShares>
            <transactionValue>
                <value>3.3125</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>A</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>0</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>I</value>
            </directOrIndirectOwnership>
            <natureOfOwnership>
                <value>By family trust</value>
                <footnoteId id="F1"/>
            </natureOfOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>Common Stock</value>
        </securityTitle>
        <transactionDate>
            <value>2003-05-09</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>S</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>26600</value>
            </transactionShares>
            <transactionValue>
                <value>16.934</value>
                <footnoteId id="F2"/>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>D</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>0</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>I</value>
            </directOrIndirectOwnership>
            <natureOfOwnership>
                <value>By family trust</value>
                <footnoteId id="F1"/>
            </natureOfOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <derivativeSecurity>
        <securityTitle>
            <value>Employee Stock Option (Right to Buy)</value>
        </securityTitle>
        <conversionOrExercisePrice>
            <value>3.3125</value>
        </conversionOrExercisePrice>
        <transactionDate>
            <value>2003-05-09</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>M</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>26600</value>
            </transactionShares>
            <transactionValue>
                <value>0</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>D</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <exerciseDate>
            <value>2000-08-03</value>
            <footnoteId id="F3"/>
        </exerciseDate>
        <expirationDate>
            <value>2009-08-03</value>
        </expirationDate>
        <underlyingSecurity>
            <underlyingSecurityTitle>
                <value>Common Stock</value>
            </underlyingSecurityTitle>
            <underlyingSecurityShares>
                <value>26600</value>
            </underlyingSecurityShares>
        </underlyingSecurity>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>40000</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>I</value>
            </directOrIndirectOwnership>
            <natureOfOwnership>
                <value>By family trust</value>
                <footnoteId id="F1"/>
            </natureOfOwnership>
        </ownershipNature>
    </derivativeSecurity>

    <footnotes>
        <footnote id="F1">The option and shares acquired upon exercise of the option are owned by the Kanofsky Family Trust dated 1-27-98, of which Mr. Kanofsky and his spouse are co-trustees.</footnote>
        <footnote id="F2">Shares were sold in various transactions upon exercise of stock options (see Table II), at a weighted average sale price per share of $16.934.</footnote>
        <footnote id="F3">The option vests in five equal annual installments commencing on August 3, 2000.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Peter C. Walsh, Attorney-in-Fact</signatureName>
        <signatureDate>2003-05-19</signatureDate>
    </ownerSignature>

</ownershipDocument>

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