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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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<SEC-DOCUMENT>0000935836-09-001444.txt : 20091209
<SEC-HEADER>0000935836-09-001444.hdr.sgml : 20091209
<ACCEPTANCE-DATETIME>20091208192147
ACCESSION NUMBER:		0000935836-09-001444
CONFORMED SUBMISSION TYPE:	D/A
PUBLIC DOCUMENT COUNT:		1
ITEM INFORMATION:		Rule 506
ITEM INFORMATION:		Investment Company Act Section 3(c)
ITEM INFORMATION:		Section 3(c)(1)
FILED AS OF DATE:		20091209
DATE AS OF CHANGE:		20091208
EFFECTIVENESS DATE:		20091209

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LYON STREET INVESTORS LP
		CENTRAL INDEX KEY:			0001452246
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE

	FILING VALUES:
		FORM TYPE:		D/A
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	021-125166
		FILM NUMBER:		091229750

	BUSINESS ADDRESS:	
		STREET 1:		744 MONTGOMERY STREET, SUITE 300
		CITY:			San Francisco
		STATE:			CA
		ZIP:			94111
		BUSINESS PHONE:		(415) 418-2211

	MAIL ADDRESS:	
		STREET 1:		744 MONTGOMERY STREET, SUITE 300
		CITY:			San Francisco
		STATE:			CA
		ZIP:			94111
</SEC-HEADER>
<DOCUMENT>
<TYPE>D/A
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<edgarSubmission>

    <schemaVersion>X0603</schemaVersion>

    <submissionType>D/A</submissionType>

    <testOrLive>LIVE</testOrLive>

    <primaryIssuer>
        <cik>0001452246</cik>
        <entityName>LYON STREET INVESTORS LP</entityName>
        <issuerAddress>
            <street1>744 Montgomery Street, Suite 300</street1>
            <city>San Francisco</city>
            <stateOrCountry>CA</stateOrCountry>
            <zipCode>94111</zipCode>
        </issuerAddress>
        <issuerPhoneNumber>(415) 418-2211</issuerPhoneNumber>
        <jurisdictionOfInc>DELAWARE</jurisdictionOfInc>
        <issuerPreviousNameList>
            <value>None</value>
        </issuerPreviousNameList>
        <edgarPreviousNameList>
            <value>None</value>
        </edgarPreviousNameList>
        <entityType>Limited Partnership</entityType>
        <yearOfInc>
            <withinFiveYears>true</withinFiveYears>
            <value>2009</value>
        </yearOfInc>
    </primaryIssuer>

    <relatedPersonsList>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>N/A</firstName>
                <lastName>Lyon Street Capital, LLC</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>744 Montgomery Street, Suite 300</street1>
                <city>San Francisco</city>
                <stateOrCountry>CA</stateOrCountry>
                <zipCode>94111</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
                <relationship>Promoter</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>General Partner</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Brian</firstName>
                <middleName>C.</middleName>
                <lastName>Freckmann</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>744 Montgomery Street, Suite 300</street1>
                <city>San Francisco</city>
                <stateOrCountry>CA</stateOrCountry>
                <zipCode>94111</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
                <relationship>Promoter</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Manager of Lyon Street Capital, LLC, General Partner</relationshipClarification>
        </relatedPersonInfo>
    </relatedPersonsList>

    <offeringData>
        <industryGroup>
            <industryGroupType>Pooled Investment Fund</industryGroupType>
            <investmentFundInfo>
                <investmentFundType>Hedge Fund</investmentFundType>
                <is40Act>false</is40Act>
            </investmentFundInfo>
        </industryGroup>
        <issuerSize>
            <aggregateNetAssetValueRange>Decline to Disclose</aggregateNetAssetValueRange>
        </issuerSize>
        <federalExemptionsExclusions>
            <item>06</item>
            <item>3C</item>
            <item>3C.1</item>
        </federalExemptionsExclusions>
        <typeOfFiling>
            <newOrAmendment>
                <isAmendment>true</isAmendment>
                <previousAccessionNumber>9999999997-08-048346</previousAccessionNumber>
            </newOrAmendment>
            <dateOfFirstSale>
                <value>2009-01-01</value>
            </dateOfFirstSale>
        </typeOfFiling>
        <durationOfOffering>
            <moreThanOneYear>true</moreThanOneYear>
        </durationOfOffering>
        <typesOfSecuritiesOffered>
            <isPooledInvestmentFundType>true</isPooledInvestmentFundType>
            <isOtherType>true</isOtherType>
            <descriptionOfOtherType>Limited partner interests</descriptionOfOtherType>
        </typesOfSecuritiesOffered>
        <businessCombinationTransaction>
            <isBusinessCombinationTransaction>false</isBusinessCombinationTransaction>
        </businessCombinationTransaction>
        <minimumInvestmentAccepted>500000</minimumInvestmentAccepted>
        <salesCompensationList></salesCompensationList>
        <offeringSalesAmounts>
            <totalOfferingAmount>500000000</totalOfferingAmount>
            <totalAmountSold>11042528</totalAmountSold>
            <totalRemaining>488957472</totalRemaining>
        </offeringSalesAmounts>
        <investors>
            <hasNonAccreditedInvestors>false</hasNonAccreditedInvestors>
            <totalNumberAlreadyInvested>17</totalNumberAlreadyInvested>
        </investors>
        <salesCommissionsFindersFees>
            <salesCommissions>
                <dollarAmount>0</dollarAmount>
                <isEstimate>true</isEstimate>
            </salesCommissions>
            <findersFees>
                <dollarAmount>0</dollarAmount>
                <isEstimate>true</isEstimate>
            </findersFees>
        </salesCommissionsFindersFees>
        <useOfProceeds>
            <grossProceedsUsed>
                <dollarAmount>0</dollarAmount>
                <isEstimate>true</isEstimate>
            </grossProceedsUsed>
            <clarificationOfResponse>None, although the general partner of the issuer receives investment management fees and a special profit allocation.</clarificationOfResponse>
        </useOfProceeds>
        <signatureBlock>
            <authorizedRepresentative>true</authorizedRepresentative>
            <signature>
                <issuerName>lyon street investors lp</issuerName>
                <signatureName>Brian C. Freckmann</signatureName>
                <nameOfSigner>Brian C. Freckmann</nameOfSigner>
                <signatureTitle>Manager of Lyon Street Capital, LLC, General Partner</signatureTitle>
                <signatureDate>2009-12-08</signatureDate>
            </signature>
        </signatureBlock>
    </offeringData>
</edgarSubmission>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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