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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,
 Bc5rCD0RAXF2/ETIVkVvL1aO1AvqpEHSRWfeR3Vn9nHxRtFlsRe04u5Ubygwk5JW
 QOWFsRKGqmfLVhE/XZDGnw==

<SEC-DOCUMENT>0001421836-08-000004.txt : 20081104
<SEC-HEADER>0001421836-08-000004.hdr.sgml : 20081104
<ACCEPTANCE-DATETIME>20081104182312
ACCESSION NUMBER:		0001421836-08-000004
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20081031
FILED AS OF DATE:		20081104
DATE AS OF CHANGE:		20081104

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			COST PLUS INC/CA/
		CENTRAL INDEX KEY:			0000798955
		STANDARD INDUSTRIAL CLASSIFICATION:	RETAIL-HOME FURNITURE, FURNISHINGS & EQUIPMENT STORES [5700]
		IRS NUMBER:				941067973
		STATE OF INCORPORATION:			CA
		FISCAL YEAR END:			0203

	BUSINESS ADDRESS:	
		STREET 1:		200 FOURTH STREET OAKLAND
		STREET 2:		SEE ADDRESS LISTED ABOVE
		CITY:			OAKLAND
		STATE:			CA
		ZIP:			94607
		BUSINESS PHONE:		5108937300

	MAIL ADDRESS:	
		STREET 1:		200 FOURTH STREET OAKLAND
		STREET 2:		SEE ADDRESS LISTED ABOVE
		CITY:			OAKLAND
		STATE:			CA
		ZIP:			94607

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Stephens Investments Holdings LLC
		CENTRAL INDEX KEY:			0001421836
		STATE OF INCORPORATION:			AR
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-14970
		FILM NUMBER:		081161951

	BUSINESS ADDRESS:	
		STREET 1:		111 CENTER STREET
		CITY:			LITTLE ROCK
		STATE:			AR
		ZIP:			72201
		BUSINESS PHONE:		501-377-2368

	MAIL ADDRESS:	
		STREET 1:		111 CENTER STREET
		CITY:			LITTLE ROCK
		STATE:			AR
		ZIP:			72201
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-10-31</periodOfReport>

    <issuer>
        <issuerCik>0000798955</issuerCik>
        <issuerName>COST PLUS INC/CA/</issuerName>
        <issuerTradingSymbol>CPWM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001421836</rptOwnerCik>
            <rptOwnerName>Stephens Investments Holdings LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>111 CENTER STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LITTLE ROCK</rptOwnerCity>
            <rptOwnerState>AR</rptOwnerState>
            <rptOwnerZipCode>72201</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>2008-10-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2229</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.55</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2489764</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes></footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Todd Ferguson, as attorney in fact for reporting person</signatureName>
        <signatureDate>2008-11-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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