-----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,
 Jsn6uUwP0+UzwcQ/tkefcEMg4cT1uklymHZOSkGjBXa2sDa+QTOpjw86ypRwjqSW
 dEDjmmlYOF9rX8VWmBvyOA==

<SEC-DOCUMENT>0001181431-03-010257.txt : 20030606
<SEC-HEADER>0001181431-03-010257.hdr.sgml : 20030606
<ACCEPTANCE-DATETIME>20030606131205
ACCESSION NUMBER:		0001181431-03-010257
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030605
FILED AS OF DATE:		20030606

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ALLEN MICHAEL J
		CENTRAL INDEX KEY:			0001190656

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-14970
		FILM NUMBER:		03735475

	BUSINESS ADDRESS:	
		STREET 1:		200 FOURTH STREET
		CITY:			OAKLAND
		STATE:			CA
		ZIP:			94607

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:			0130

	BUSINESS ADDRESS:	
		STREET 1:		201 CLAY ST
		STREET 2:		P O BOX 23350
		CITY:			OAKLAND
		STATE:			CA
		ZIP:			94607
		BUSINESS PHONE:		4158937300

	MAIL ADDRESS:	
		STREET 1:		201 CLAY ST
		STREET 2:		P O BOX 23350
		CITY:			OAKLAND
		STATE:			CA
		ZIP:			94623
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>rrd10606.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0101</schemaVersion>

    <documentType>4</documentType>
<periodOfReport>2003-06-05</periodOfReport>
<notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000798955</issuerCik>
        <issuerName>COST PLUS INC/CA/</issuerName>
        <issuerTradingSymbol>CPWM</issuerTradingSymbol></issuer>
<reportingOwner>
<reportingOwnerId>
            <rptOwnerCik>0001190656</rptOwnerCik>
            <rptOwnerName>ALLEN MICHAEL J</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>Senior VP, Store Operations</officerTitle>
<otherText></otherText></reportingOwnerRelationship></reportingOwner>
<nonDerivativeSecurity>
<securityTitle>
<value>Cost Plus Common Stock</value></securityTitle>
<transactionDate>
<value>2003-06-05</value></transactionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>M</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved></transactionCoding>
<transactionTimeliness>
<value></value></transactionTimeliness>
<transactionAmounts>
<transactionShares>
<value>3375</value></transactionShares>
<transactionValue>
<value>7.00</value></transactionValue>
<transactionAcquiredDisposedCode>
<value>A</value></transactionAcquiredDisposedCode></transactionAmounts>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>0</value></sharesOwnedFollowingTransaction></postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value></directOrIndirectOwnership>
<natureOfOwnership>
<value></value></natureOfOwnership></ownershipNature></nonDerivativeSecurity>
<nonDerivativeSecurity>
<securityTitle>
<value>Cost Plus Common Stock</value></securityTitle>
<transactionDate>
<value>2003-06-05</value></transactionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>M</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved></transactionCoding>
<transactionTimeliness>
<value></value></transactionTimeliness>
<transactionAmounts>
<transactionShares>
<value>2288</value></transactionShares>
<transactionValue>
<value>2.5631</value></transactionValue>
<transactionAcquiredDisposedCode>
<value>A</value></transactionAcquiredDisposedCode></transactionAmounts>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>0</value></sharesOwnedFollowingTransaction></postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value></directOrIndirectOwnership>
<natureOfOwnership>
<value></value></natureOfOwnership></ownershipNature></nonDerivativeSecurity>
<nonDerivativeSecurity>
<securityTitle>
<value>Cost Plus Common Stock</value></securityTitle>
<transactionDate>
<value>2003-06-05</value></transactionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>S</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved></transactionCoding>
<transactionTimeliness>
<value></value></transactionTimeliness>
<transactionAmounts>
<transactionShares>
<value>5663</value></transactionShares>
<transactionValue>
<value>36.1905</value></transactionValue>
<transactionAcquiredDisposedCode>
<value>D</value></transactionAcquiredDisposedCode></transactionAmounts>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>0</value></sharesOwnedFollowingTransaction></postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value></directOrIndirectOwnership>
<natureOfOwnership>
<value></value></natureOfOwnership></ownershipNature></nonDerivativeSecurity>
<derivativeSecurity>
<securityTitle>
<value>Employee Stock Option (right to buy)</value></securityTitle>
<conversionOrExercisePrice>
<value>7.00</value></conversionOrExercisePrice>
<transactionDate>
<value>2003-06-05</value></transactionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>M</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved></transactionCoding>
<transactionAmounts>
<transactionShares>
<value>3375</value></transactionShares>
<transactionValue>
<value>7.00</value></transactionValue>
<transactionAcquiredDisposedCode>
<value>D</value></transactionAcquiredDisposedCode></transactionAmounts>
<exerciseDate>
<value>1998-03-27</value></exerciseDate>
<expirationDate>
<value>2007-03-27</value></expirationDate>
<underlyingSecurity>
<underlyingSecurityTitle>
<value>Cost Plus Common Stock</value></underlyingSecurityTitle>
<underlyingSecurityShares>
<value>3375</value></underlyingSecurityShares></underlyingSecurity>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>0</value></sharesOwnedFollowingTransaction></postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value></directOrIndirectOwnership>
<natureOfOwnership>
<value></value></natureOfOwnership></ownershipNature></derivativeSecurity>
<derivativeSecurity>
<securityTitle>
<value>Employee Stock Option (right to buy)</value></securityTitle>
<conversionOrExercisePrice>
<value>2.5631</value></conversionOrExercisePrice>
<transactionDate>
<value>2003-06-05</value></transactionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>M</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved></transactionCoding>
<transactionAmounts>
<transactionShares>
<value>2288</value></transactionShares>
<transactionValue>
<value>2.5631</value></transactionValue>
<transactionAcquiredDisposedCode>
<value>D</value></transactionAcquiredDisposedCode></transactionAmounts>
<exerciseDate>
<value>1996-03-17</value></exerciseDate>
<expirationDate>
<value>2005-03-17</value></expirationDate>
<underlyingSecurity>
<underlyingSecurityTitle>
<value>Cost Plus Common Stock</value></underlyingSecurityTitle>
<underlyingSecurityShares>
<value>2288</value></underlyingSecurityShares></underlyingSecurity>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>0</value></sharesOwnedFollowingTransaction></postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value></directOrIndirectOwnership>
<natureOfOwnership>
<value></value></natureOfOwnership></ownershipNature></derivativeSecurity>
<ownerSignature>
<signatureName>Christopher M. Miller, Attorney-in-Fact for Mike Allen</signatureName>
<signatureDate>2003-06-06</signatureDate></ownerSignature></ownershipDocument>


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