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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,
 EriL9gTNVyAPOWEIegUkPpJnPyVWVAy1BhTtyUNcMbDnOo8c9dnEXcP/6okX7d+6
 tGfiNRtJFSU8QouhGeLF5A==

<SEC-DOCUMENT>0001258119-07-000004.txt : 20071109
<SEC-HEADER>0001258119-07-000004.hdr.sgml : 20071109
<ACCEPTANCE-DATETIME>20071109141725
ACCESSION NUMBER:		0001258119-07-000004
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20071108
FILED AS OF DATE:		20071109
DATE AS OF CHANGE:		20071109

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MoSys, Inc.
		CENTRAL INDEX KEY:			0000890394
		STANDARD INDUSTRIAL CLASSIFICATION:	SEMICONDUCTORS & RELATED DEVICES [3674]
		IRS NUMBER:				770291941
		STATE OF INCORPORATION:			CA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		755 N MATIHILDA AVENUE
		CITY:			SUNNYVALE
		STATE:			CA
		ZIP:			94085
		BUSINESS PHONE:		408 731 1800

	MAIL ADDRESS:	
		STREET 1:		755 N MATIHILDA AVENUE
		CITY:			SUNNYVALE
		STATE:			CA
		ZIP:			94085

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MONOLITHIC SYSTEM TECHNOLOGY INC
		DATE OF NAME CHANGE:	19960613

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Silvestri Chester Joseph
		CENTRAL INDEX KEY:			0001335080

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-32929
		FILM NUMBER:		071230441

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		650-941-4092

	MAIL ADDRESS:	
		STREET 1:		13935 LA PALOMA RD.
		CITY:			LOS ALTOS HILLS
		STATE:			CA
		ZIP:			94022
</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>2007-11-08</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0000890394</issuerCik>
        <issuerName>MoSys, Inc.</issuerName>
        <issuerTradingSymbol>mosy</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001335080</rptOwnerCik>
            <rptOwnerName>Silvestri Chester Joseph</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>755 N. MATHILDA AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>C/O MOSYS, INC.</rptOwnerStreet2>
            <rptOwnerCity>SUNNYVALE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94085</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Executive Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <ownerSignature>
        <signatureName>Chester Silvestri</signatureName>
        <signatureDate>2007-11-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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