<?xml version="1.0"?>
<edgarSubmission>

    <schemaVersion>X0301</schemaVersion>

    <submissionType>D/A</submissionType>

    <testOrLive>LIVE</testOrLive>

    <primaryIssuer>
        <cik>0001436801</cik>
        <entityName>ALERION INVESTMENT PARTNERS II LP</entityName>
        <issuerAddress>
            <street1>105 ROWAYTON AVENUE</street1>
            <street2></street2>
            <city>ROWAYTON</city>
            <stateOrCountry>CT</stateOrCountry>
            <zipCode>06853</zipCode>
        </issuerAddress>
        <issuerPhoneNumber>203-838-6700</issuerPhoneNumber>
        <issuerPreviousNameList>
            <value>None</value>
        </issuerPreviousNameList>
        <jurisdictionOfInc>DE</jurisdictionOfInc>
        <entityType>Limited Partnership</entityType>
        <yearOfInc>
            <withinFiveYears>true</withinFiveYears>
            <value>2008</value>
        </yearOfInc>
    </primaryIssuer>

    <relatedPersonsList>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>LLC</firstName>
                <middleName></middleName>
                <lastName>Alerion Investment Managers II,</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>105 Rowayton Avenue</street1>
                <street2></street2>
                <city>Rowayton</city>
                <stateOrCountry>CT</stateOrCountry>
                <zipCode>06853</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
    </relatedPersonsList>

    <offeringData>
        <industryGroup>
            <industryGroupType>Pooled Investment Fund</industryGroupType>
            <investmentFundInfo>
                <investmentFundType>Venture Capital Fund</investmentFundType>
                <is40Act>false</is40Act>
            </investmentFundInfo>
        </industryGroup>
        <issuerSize>
            <revenueRange>Decline to Disclose</revenueRange>
        </issuerSize>
        <federalExemptionsExclusions>
            <item>06</item>
            <item>3C</item>
            <item>3C.7</item>
        </federalExemptionsExclusions>
        <typeOfFiling>
            <newOrAmendment>
                <isAmendment>true</isAmendment>
                <previousAccessionNumber>9999999997-08-027063</previousAccessionNumber>
            </newOrAmendment>
            <dateOfFirstSale>
                <value>2008-06-03</value>
            </dateOfFirstSale>
        </typeOfFiling>
        <durationOfOffering>
            <moreThanOneYear>true</moreThanOneYear>
        </durationOfOffering>
        <typesOfSecuritiesOffered>
            <isPooledInvestmentFundType>true</isPooledInvestmentFundType>
        </typesOfSecuritiesOffered>
        <businessCombinationTransaction>
            <isBusinessCombinationTransaction>false</isBusinessCombinationTransaction>
            <clarificationOfResponse></clarificationOfResponse>
        </businessCombinationTransaction>
        <minimumInvestmentAccepted>250000</minimumInvestmentAccepted>
        <salesCompensationList>
            <recipient>
                <recipientName>Rick Hopkins</recipientName>
                <recipientCRDNumber>None</recipientCRDNumber>
                <associatedBDName>None</associatedBDName>
                <associatedBDCRDNumber>None</associatedBDCRDNumber>
                <recipientAddress>
                    <street1>3440 Toringdon Way</street1>
                    <street2>Suite 308 C/O Keane Capital Management</street2>
                    <city>Charlotte</city>
                    <stateOrCountry>NC</stateOrCountry>
                    <zipCode>28277</zipCode>
                </recipientAddress>
                <statesOfSolicitationList>
                    <state>FL</state>
                    <state>MD</state>
                    <state>NC</state>
                    <state>TN</state>
                    <state>TX</state>
                </statesOfSolicitationList>
            </recipient>
            <recipient>
                <recipientName>Joe Webster</recipientName>
                <recipientCRDNumber>None</recipientCRDNumber>
                <associatedBDName>None</associatedBDName>
                <associatedBDCRDNumber>None</associatedBDCRDNumber>
                <recipientAddress>
                    <street1>c/o Dye Preserve</street1>
                    <street2>1808 Colony Way</street2>
                    <city>Jupiter</city>
                    <stateOrCountry>FL</stateOrCountry>
                    <zipCode>33478</zipCode>
                </recipientAddress>
                <statesOfSolicitationList>
                    <state>MD</state>
                    <state>NY</state>
                    <state>OH</state>
                    <state>SC</state>
                </statesOfSolicitationList>
            </recipient>
        </salesCompensationList>
        <offeringSalesAmounts>
            <totalOfferingAmount>100000000</totalOfferingAmount>
            <totalAmountSold>35735000</totalAmountSold>
            <totalRemaining>64265000</totalRemaining>
            <clarificationOfResponse></clarificationOfResponse>
        </offeringSalesAmounts>
        <investors>
            <hasNonAccreditedInvestors>false</hasNonAccreditedInvestors>
            <totalNumberAlreadyInvested>28</totalNumberAlreadyInvested>
        </investors>
        <salesCommissionsFindersFees>
            <salesCommissions>
                <dollarAmount>0</dollarAmount>
            </salesCommissions>
            <findersFees>
                <dollarAmount>226000</dollarAmount>
            </findersFees>
            <clarificationOfResponse></clarificationOfResponse>
        </salesCommissionsFindersFees>
        <useOfProceeds>
            <grossProceedsUsed>
                <dollarAmount>0</dollarAmount>
            </grossProceedsUsed>
            <clarificationOfResponse></clarificationOfResponse>
        </useOfProceeds>
        <signatureBlock>
            <authorizedRepresentative>false</authorizedRepresentative>
            <signature>
                <issuerName>ALERION INVESTMENT PARTNERS II LP</issuerName>
                <signatureName>/S/ Norman Tsang</signatureName>
                <nameOfSigner>Norman Tsang</nameOfSigner>
                <signatureTitle>Managing Member of the General Partner</signatureTitle>
                <signatureDate>2009-05-27</signatureDate>
            </signature>
        </signatureBlock>
    </offeringData>
</edgarSubmission>
