-----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,
 BPpIby2FnCR8juNQDjUnbUTrCItLKc1/NvA7CwLGQ0BkGBVFpQSgpHQHF3Y7WN/9
 Kh1aMcECNiqTR6SYgA7rrQ==

<SEC-DOCUMENT>0001127602-10-021530.txt : 20100817
<SEC-HEADER>0001127602-10-021530.hdr.sgml : 20100817
<ACCEPTANCE-DATETIME>20100817183019
ACCESSION NUMBER:		0001127602-10-021530
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100811
FILED AS OF DATE:		20100817
DATE AS OF CHANGE:		20100817

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			NEILSEN RAY H
		CENTRAL INDEX KEY:			0001382070

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-22494
		FILM NUMBER:		101024213

	MAIL ADDRESS:	
		STREET 1:		C/O AMERISTAR CASINOS, INC.
		STREET 2:		3773 HOWARD HUGHES PARKWAY, SUITE 490S
		CITY:			LAS VEGAS
		STATE:			NV
		ZIP:			89169

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:			89169
		BUSINESS PHONE:		7025677000

	MAIL ADDRESS:	
		STREET 1:		3773 HOWARD HUGHES PKWY
		STREET 2:		SUITE 490 SOUTH
		CITY:			LAS VEGAS
		STATE:			NV
		ZIP:			89169
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>form4a.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2010-08-11</periodOfReport>

    <dateOfOriginalSubmission>2010-08-13</dateOfOriginalSubmission>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001382070</rptOwnerCik>
            <rptOwnerName>NEILSEN RAY H</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3773 HOWARD HUGHES PKWY</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 490S</rptOwnerStreet2>
            <rptOwnerCity>LAS VEGAS</rptOwnerCity>
            <rptOwnerState>NV</rptOwnerState>
            <rptOwnerZipCode>89169</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <officerTitle>Chairman of the Board</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-08-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>9360</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>16.14</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>197359</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">On August 13, 2010, the reporting person filed a Form 4 reporting the forfeiture, in satisfaction of tax withholding liability, of shares deliverable upon vesting of restricted stock units. The tax withholding calculations used in preparation of that filing, and therefore the numbers of shares reported as forfeited, were in error. This amendment corrects the number of shares forfeited.</footnote>
        <footnote id="F2">Balance includes previously reported restricted stock units and performance share units, each of which constitutes the right to receive one share of common stock in the future.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Peter C. Walsh, Attorney-in-Fact</signatureName>
        <signatureDate>2010-08-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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