-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 Tg9FIs9EOzVBzNxvVTv7ZLfkmzTZMwnoBg2cgmShQ+ZA7C+X+OBptCjwr2PrmZEO
 af1jKEBarTHC5PEBxQ3zlQ==

<SEC-DOCUMENT>0001282498-05-000001.txt : 20050127
<SEC-HEADER>0001282498-05-000001.hdr.sgml : 20050127
<ACCEPTANCE-DATETIME>20050127140226
ACCESSION NUMBER:		0001282498-05-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050126
FILED AS OF DATE:		20050127
DATE AS OF CHANGE:		20050127

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			JAMES C SHELTON
		CENTRAL INDEX KEY:			0001053645

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-10843
		FILM NUMBER:		05553240

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		9547719696

	MAIL ADDRESS:	
		STREET 1:		GROUP LONG DISTANCE INC
		STREET 2:		1451 W CYPRESS CREEK RD STE 200
		CITY:			FT LAUDERDALE
		STATE:			FL
		ZIP:			33309

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CSP INC /MA/
		CENTRAL INDEX KEY:			0000356037
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-COMPUTER INTEGRATED SYSTEMS DESIGN [7373]
		IRS NUMBER:				042441294
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			0831

	BUSINESS ADDRESS:	
		STREET 1:		43 MANNING ROAD
		CITY:			BILLERICA
		STATE:			MA
		ZIP:			01821
		BUSINESS PHONE:		9786637598

	MAIL ADDRESS:	
		STREET 1:		43 MANNING ROAD
		CITY:			BILLERICA
		STATE:			MA
		ZIP:			01821
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-01-26</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000356037</issuerCik>
        <issuerName>CSP INC /MA/</issuerName>
        <issuerTradingSymbol>CSPI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001053645</rptOwnerCik>
            <rptOwnerName>JAMES C SHELTON</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>GROUP LONG DISTANCE INC</rptOwnerStreet1>
            <rptOwnerStreet2>1451 W CYPRESS CREEK RD STE 200</rptOwnerStreet2>
            <rptOwnerCity>FT LAUDERDALE</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33309</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2005-01-26</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.65</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4900</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Exercise of stock options</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>C. Shelton James</signatureName>
        <signatureDate>2005-01-26</signatureDate>
    </ownerSignature>
</ownershipDocument>

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