<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:ns2="http://www.sec.gov/edgar/common">
    <headerData>
        <submissionType>144</submissionType>
        <filerInfo>
            <filer>
                <filerCredentials>
                    <cik>0001480560</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>



        </filerInfo>
    </headerData>
    <formData>
        <issuerInfo>
            <issuerCik>0001013857</issuerCik>
            <issuerName>PEGASYSTEMS INC</issuerName>
            <secFileNumber>001-11859</secFileNumber>
            <issuerAddress>
                <ns2:street1>One Main Street</ns2:street1>
                <ns2:city>Cambridge</ns2:city>
                <ns2:stateOrCountry>MA</ns2:stateOrCountry>
                <ns2:zipCode>02142</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>6173749600</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>LEON TREFLER</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Officer</relationshipToIssuer>
            </relationshipsToIssuer>
        </issuerInfo>
        <securitiesInformation>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <brokerOrMarketmakerDetails>
                <name>Morgan Stanley Smith Barney LLC Executive Financial Services</name>
                <address>
                    <ns2:street1>1 New York Plaza</ns2:street1>
                    <ns2:street2>38th Fl.</ns2:street2>
                    <ns2:city>New York</ns2:city>
                    <ns2:stateOrCountry>NY</ns2:stateOrCountry>
                    <ns2:zipCode>10004</ns2:zipCode>
                </address>
            </brokerOrMarketmakerDetails>
            <noOfUnitsSold>3008</noOfUnitsSold>
            <aggregateMarketValue>195159.04</aggregateMarketValue>
            <noOfUnitsOutstanding>83905034</noOfUnitsOutstanding>
            <approxSaleDate>02/20/2024</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>03/07/2019</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted Stock Units</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>3008</amountOfSecuritiesAcquired>
            <paymentDate>03/07/2019</paymentDate>
            <natureOfPayment>N/A</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales Plan for LEON TREFLER</name>
                <address>
                    <ns2:street1>One Main Street</ns2:street1>
                    <ns2:city>Cambridge</ns2:city>
                    <ns2:stateOrCountry>MA</ns2:stateOrCountry>
                    <ns2:zipCode>02142</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>COMMON</securitiesClassTitle>
            <saleDate>12/01/2023</saleDate>
            <amountOfSecuritiesSold>810</amountOfSecuritiesSold>
            <grossProceeds>42444.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <remarks>The securities to be sold were acquired upon the vesting of restricted stock units during the period of 03/07/2019 through 09/06/2023.
</remarks>
        <noticeSignature>
            <noticeDate>02/20/2024</noticeDate>
            <planAdoptionDates>
                <planAdoptionDate>11/17/2023</planAdoptionDate>
            </planAdoptionDates>
            <signature>/s/ Leon Trefler</signature>
        </noticeSignature>
    </formData>
</edgarSubmission>
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144
0001480560
XXXXXXXX
LIVE
0001013857
PEGASYSTEMS INC
001-11859
One Main Street
Cambridge
MA
02142
6173749600
LEON TREFLER
Officer
Common
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
38th Fl.
New York
NY
10004
3008
195159.04
83905034
02/20/2024
NASDAQ
Common
03/07/2019
Restricted Stock Units
Issuer
N
3008
03/07/2019
N/A
N
10b5-1 Sales Plan for LEON TREFLER
One Main Street
Cambridge
MA
02142
COMMON
12/01/2023
810
42444.00
The securities to be sold were acquired upon the vesting of restricted stock units during the period of 03/07/2019 through 09/06/2023.
02/20/2024
11/17/2023
/s/ Leon Trefler