-----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,
 JDtGQBdSdltPoqfihi4OjYdqKE0U71iUw5Utmf0NWiiEYCl6ucQidBBowGPNInt0
 c861qal3n2ESnlt7Ad2Rrg==

<SEC-DOCUMENT>0001209841-03-000001.txt : 20031212
<SEC-HEADER>0001209841-03-000001.hdr.sgml : 20031212
<ACCEPTANCE-DATETIME>20031212133721
ACCESSION NUMBER:		0001209841-03-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031211
FILED AS OF DATE:		20031212

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			STEINBAUER THOMAS M
		CENTRAL INDEX KEY:			0001209841

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-22494
		FILM NUMBER:		031051374

	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
<SEQUENCE>1
<FILENAME>c0001209841d20031211f4f.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<ownershipDocument><schemaVersion>X0201</schemaVersion>    <documentType>4</documentType><periodOfReport>2003-12-11</periodOfReport><notSubjectToSection16>0</notSubjectToSection16><issuer><issuerCik>0000912145</issuerCik><issuerName>AMERISTAR CASINOS INC</issuerName>        <issuerTradingSymbol>ASCA</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0001209841</rptOwnerCik><rptOwnerName>STEINBAUER THOMAS M</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>3773 HOWARD HUGHES PKWY</rptOwnerStreet1><rptOwnerStreet2>SUITE 490S</rptOwnerStreet2><rptOwnerCity>LAS VEGAS</rptOwnerCity><rptOwnerState>NV</rptOwnerState><rptOwnerZipCode>89109</rptOwnerZipCode><rptOwnerStateDescription></rptOwnerStateDescription></reportingOwnerAddress><reportingOwnerRelationship><isDirector>1</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>Senior V.P. of Finance</officerTitle><otherText></otherText></reportingOwnerRelationship
></reportingOwner><nonDerivativeTable></nonDerivativeTable><derivativeTable><derivativeTransaction><securityTitle><value>Stock Options (Right to buy)</value></securityTitle><conversionOrExercisePrice><value>13.935</value></conversionOrExercisePrice><transactionDate><value>2003-12-11</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>13350</value></transactionShares><transactionPricePerShare><value>0</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2003-12-19</value><footnoteId id="F1"/></exerciseDate><expirationDate><value>2012-12-20</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><
value>13350</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>13350</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwnership></ownershipNature></derivativeTransaction><derivativeTransaction><securityTitle><value>Stock Options (Right to buy)</value></securityTitle><conversionOrExercisePrice><value>23.055</value></conversionOrExercisePrice><transactionDate><value>2003-12-11</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>11420</value></transactionShares><transactionPricePerShare><value>0</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></
transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2004-12-10</value><footnoteId id="F2"/></exerciseDate><expirationDate><value>2013-12-11</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>11420</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>11420</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwnership></ownershipNature></derivativeTransaction></derivativeTable><footnotes><footnote id="F1">The option will vest in five equal, annual installments commencing on December 19, 2003.</footnote><footnote id="F2">The option will vest in five equal, annual installments commencing on December 10, 2004.</footnote></footnotes><ownerSignature><signatureName>Thomas  Steinbauer<
/signatureName><signatureDate>2003-12-11</signatureDate></ownerSignature></ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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