<?xml version="1.0" encoding="UTF-8"?>
<edgarSubmission xmlns="http://www.sec.gov/edgar/maifiler" xmlns:com="http://www.sec.gov/edgar/common_ma" xmlns:com1="http://www.sec.gov/edgar/common">
  <headerData>
    <submissionType>MA-I/A</submissionType>
    <filerInfo>
      <com:filer>
        <com1:filerId>0000724683</com1:filerId>
        <com1:filerCcc>XXXXXXXX</com1:filerCcc>
      </com:filer>
      <com:contact>
        <com1:name>Madeline Grinnell</com1:name>
        <com1:phoneNumber>6123036523</com1:phoneNumber>
      </com:contact>
      <com:contactEmail>madeline.grinnell@psc.com</com:contactEmail>
      <com:notifications>
        <com1:internetNotificationAddress>registration@psc.com</com1:internetNotificationAddress>
      </com:notifications>
    </filerInfo>
  </headerData>
  <formData>
    <isAmendment>N</isAmendment>
    <isIndividual>N</isIndividual>
    <applicantName>
      <com:firstName>JENNIFER</com:firstName>
      <com:middleName>NMN</com:middleName>
      <com:lastName>HAN</com:lastName>
    </applicantName>
    <applicantCrdNum>6934085</applicantCrdNum>
    <hasMoreThanOneAdvisoryFirms>N</hasMoreThanOneAdvisoryFirms>
    <noOfAdvisoryFirms>1</noOfAdvisoryFirms>
    <municipalAdvisorOffices>
      <municipalAdvisorOffice>
        <municipalFirm>
          <municipalFiler>
            <filerId>0000724683</filerId>
          </municipalFiler>
          <municipalFirmName>PIPER JAFFRAY &amp; CO.</municipalFirmName>
          <recentEmploymentCommencedDate>04-02-2018</recentEmploymentCommencedDate>
          <isIndependentRelatioship>N</isIndependentRelatioship>
        </municipalFirm>
        <maRegistration>
          <secRegistration>
            <com:fileNumber>867-01178</com:fileNumber>
          </secRegistration>
        </maRegistration>
        <advisorOffices>
          <advisorOffice>
            <locationInfo>LOCATED</locationInfo>
            <startDate>04-02-2018</startDate>
            <addressInfo>
              <com:address>
                <com1:street1>1420 FIFTH AVE</com1:street1>
                <com1:street2>SUITE 1425</com1:street2>
                <com1:city>SEATTLE</com1:city>
                <com1:stateOrCountry>WA</com1:stateOrCountry>
                <com1:zipCode>98101</com1:zipCode>
              </com:address>
            </addressInfo>
          </advisorOffice>
        </advisorOffices>
      </municipalAdvisorOffice>
    </municipalAdvisorOffices>
    <residentialHistory></residentialHistory>
    <employmentHistory>
      <currentEmployer>
        <startDate>04-2018</startDate>
        <name>PIPER JAFFRAY &amp; CO.</name>
        <addressInfo>
          <city>SEATTLE</city>
          <stateOrCountry>
            <com1:stateOrCountry>WA</com1:stateOrCountry>
          </stateOrCountry>
          <zipCode>98101</zipCode>
        </addressInfo>
        <isRelatedToMunicipalAdvisor>Y</isRelatedToMunicipalAdvisor>
        <isRelatedToInvestment>Y</isRelatedToInvestment>
        <positionDescription>PUBLIC FINANCE INVESTMENT BANKING</positionDescription>
      </currentEmployer>
      <priorEmployers>
        <priorEmployer>
          <startDate>10-2017</startDate>
          <endDate>02-2018</endDate>
          <name>BLOCKCHAIN RESEARCH INSTITUTE - TORONTO</name>
          <addressInfo>
            <city>TORONTO</city>
            <stateOrCountry>
              <com1:stateOrCountry>Z4</com1:stateOrCountry>
            </stateOrCountry>
            <zipCode>NA</zipCode>
          </addressInfo>
          <isRelatedToMunicipalAdvisor>N</isRelatedToMunicipalAdvisor>
          <isRelatedToInvestment>N</isRelatedToInvestment>
          <positionDescription>CONTRACT RESEARCHER</positionDescription>
        </priorEmployer>
        <priorEmployer>
          <startDate>06-2016</startDate>
          <endDate>08-2017</endDate>
          <name>BRYAN CAVE LLP</name>
          <addressInfo>
            <city>SAN FRANCISCO</city>
            <stateOrCountry>
              <com1:stateOrCountry>CA</com1:stateOrCountry>
            </stateOrCountry>
            <zipCode>94111</zipCode>
          </addressInfo>
          <isRelatedToMunicipalAdvisor>N</isRelatedToMunicipalAdvisor>
          <isRelatedToInvestment>N</isRelatedToInvestment>
          <positionDescription>MARKETING ASSISTANT</positionDescription>
        </priorEmployer>
        <priorEmployer>
          <startDate>11-2015</startDate>
          <endDate>05-2016</endDate>
          <name>CENTER FOR LAW, ENERGY &amp; THE ENVIRONMENT</name>
          <addressInfo>
            <city>BERKELEY</city>
            <stateOrCountry>
              <com1:stateOrCountry>CA</com1:stateOrCountry>
            </stateOrCountry>
            <zipCode>94705</zipCode>
          </addressInfo>
          <isRelatedToMunicipalAdvisor>N</isRelatedToMunicipalAdvisor>
          <isRelatedToInvestment>N</isRelatedToInvestment>
          <positionDescription>STUDENT ASSISTANT</positionDescription>
        </priorEmployer>
        <priorEmployer>
          <startDate>05-2015</startDate>
          <endDate>05-2016</endDate>
          <name>RUTHERFORD + CHEKENE</name>
          <addressInfo>
            <city>SAN FRANCISCO</city>
            <stateOrCountry>
              <com1:stateOrCountry>CA</com1:stateOrCountry>
            </stateOrCountry>
            <zipCode>94111</zipCode>
          </addressInfo>
          <isRelatedToMunicipalAdvisor>N</isRelatedToMunicipalAdvisor>
          <isRelatedToInvestment>N</isRelatedToInvestment>
          <positionDescription>STUDENT INTERN</positionDescription>
        </priorEmployer>
        <priorEmployer>
          <startDate>08-2012</startDate>
          <endDate>05-2016</endDate>
          <name>UNIVERSITY OF CALIFORNIA BERKELEY</name>
          <addressInfo>
            <city>BERKELEY</city>
            <stateOrCountry>
              <com1:stateOrCountry>CA</com1:stateOrCountry>
            </stateOrCountry>
            <zipCode>94720</zipCode>
          </addressInfo>
          <isRelatedToMunicipalAdvisor>N</isRelatedToMunicipalAdvisor>
          <isRelatedToInvestment>N</isRelatedToInvestment>
          <positionDescription>STUDENT</positionDescription>
        </priorEmployer>
        <priorEmployer>
          <startDate>09-2008</startDate>
          <endDate>06-2012</endDate>
          <name>PENINSULA HIGH SCHOOL</name>
          <addressInfo>
            <city>GIG HARBOR</city>
            <stateOrCountry>
              <com1:stateOrCountry>WA</com1:stateOrCountry>
            </stateOrCountry>
            <zipCode>98332</zipCode>
          </addressInfo>
          <isRelatedToMunicipalAdvisor>N</isRelatedToMunicipalAdvisor>
          <isRelatedToInvestment>N</isRelatedToInvestment>
          <positionDescription>STUDENT</positionDescription>
        </priorEmployer>
      </priorEmployers>
    </employmentHistory>
    <isEngagedInOtherBusiness>Y</isEngagedInOtherBusiness>
    <otherBusinesses>
      <otherBusiness>
        <startDate>07-2018</startDate>
        <name>SAKE SUSHI AND GRILL</name>
        <addressInfo>
          <com1:street1>5738 26TH NORTH STREET</com1:street1>
          <com1:street2>SUITE 5A</com1:street2>
          <com1:city>TACOMA</com1:city>
          <com1:stateOrCountry>WA</com1:stateOrCountry>
          <com1:zipCode>98407</com1:zipCode>
        </addressInfo>
        <isRelatedToMunicipalAdvisor>N</isRelatedToMunicipalAdvisor>
        <isRelatedToInvestment>N</isRelatedToInvestment>
        <natureOfBusiness>RESTAURANT</natureOfBusiness>
        <positionDescription>SOLE PROPRIETOR</positionDescription>
        <approximateHoursOrMonths>60</approximateHoursOrMonths>
        <dutiesDescription>MARKETING, WAITRESSING, ENSURING LICENSES ARE UP TO DATE</dutiesDescription>
      </otherBusiness>
      <otherBusiness>
        <startDate>04-2019</startDate>
        <name>Blockchain Research Institute</name>
        <addressInfo>
          <com1:street1>111 Peter Street</com1:street1>
          <com1:street2>Unit 503</com1:street2>
          <com1:city>Toronto</com1:city>
          <com1:stateOrCountry>Z4</com1:stateOrCountry>
          <com1:zipCode>M5V 2H1</com1:zipCode>
        </addressInfo>
        <isRelatedToMunicipalAdvisor>N</isRelatedToMunicipalAdvisor>
        <isRelatedToInvestment>N</isRelatedToInvestment>
        <natureOfBusiness>Research organization</natureOfBusiness>
        <positionDescription>Researcher</positionDescription>
        <approximateHoursOrMonths>15</approximateHoursOrMonths>
        <dutiesDescription>Research; not investment related</dutiesDescription>
      </otherBusiness>
    </otherBusinesses>
    <disclosureQuestions>
      <criminalDisclosure>
        <criminalDisclosureCommonQuestion>
          <com:isConvictedOfFelony>N</com:isConvictedOfFelony>
          <com:isChargedWithFelony>N</com:isChargedWithFelony>
          <com:isOrgConvictedOfFelony>N</com:isOrgConvictedOfFelony>
          <com:isOrgChargedWithFelony>N</com:isOrgChargedWithFelony>
        </criminalDisclosureCommonQuestion>
        <isConvictedOfMisdemeanor>N</isConvictedOfMisdemeanor>
        <isChargedWithMisdemeanor>N</isChargedWithMisdemeanor>
        <isOrgConvictedOfMisdemeanor>N</isOrgConvictedOfMisdemeanor>
        <isOrgChargedWithMisdemeanor>N</isOrgChargedWithMisdemeanor>
      </criminalDisclosure>
      <regulatoryDisclosure>
        <regulatoryDisclosureCommonQuestion>
          <com:isMadeFalseStatement>N</com:isMadeFalseStatement>
          <com:isViolatedRegulation>N</com:isViolatedRegulation>
          <com:isCauseOfDenial>N</com:isCauseOfDenial>
          <com:isOrderAgainst>N</com:isOrderAgainst>
          <com:isImposedPenalty>N</com:isImposedPenalty>
          <com:isUnEthical>N</com:isUnEthical>
          <com:isFoundInViolationOfRegulation>N</com:isFoundInViolationOfRegulation>
          <com:isFoundInCauseOfDenial>N</com:isFoundInCauseOfDenial>
          <com:isOrderAgainstActivity>N</com:isOrderAgainstActivity>
          <com:isDeniedLicense>N</com:isDeniedLicense>
          <com:isFoundMadeFalseStatement>N</com:isFoundMadeFalseStatement>
          <com:isFoundInViolationOfRules>N</com:isFoundInViolationOfRules>
          <com:isFoundInCauseOfSuspension>N</com:isFoundInCauseOfSuspension>
          <com:isDiscipliend>N</com:isDiscipliend>
          <com:isAuthorizedToActAttorney>N</com:isAuthorizedToActAttorney>
          <com:isRegulatoryComplaint>N</com:isRegulatoryComplaint>
        </regulatoryDisclosureCommonQuestion>
        <isViolatedSecurityAct>N</isViolatedSecurityAct>
        <isWillFullyAided>N</isWillFullyAided>
        <isFailedToSupervise>N</isFailedToSupervise>
        <isFoundWillFullyAided>N</isFoundWillFullyAided>
        <isAssociationBared>N</isAssociationBared>
        <isFinalOrder>N</isFinalOrder>
        <isWillFullyViolatedSecurityAct>N</isWillFullyViolatedSecurityAct>
        <isFailedResonably>N</isFailedResonably>
      </regulatoryDisclosure>
      <investigationDisclosure>
        <isInvestigated>N</isInvestigated>
      </investigationDisclosure>
      <civilDisclosure>
        <com:isEnjoined>N</com:isEnjoined>
        <com:isFoundInViolationOfRegulation>N</com:isFoundInViolationOfRegulation>
        <com:isDismissed>N</com:isDismissed>
        <com:isNamedInCivilProceeding>N</com:isNamedInCivilProceeding>
      </civilDisclosure>
      <complaintDisclosure>
        <isComplaintPending>N</isComplaintPending>
        <isComplaintSettled>N</isComplaintSettled>
        <isFraudCasePending>N</isFraudCasePending>
        <isFraudCaseResultedAward>N</isFraudCaseResultedAward>
        <isFraudCaseSettled>N</isFraudCaseSettled>
      </complaintDisclosure>
      <terminationDisclosure>
        <isViloatedIndustryStandard>N</isViloatedIndustryStandard>
        <isInvolvedInFraud>N</isInvolvedInFraud>
        <isFailedToSupervise>N</isFailedToSupervise>
      </terminationDisclosure>
      <financialDisclosure>
        <isCompromised>N</isCompromised>
        <isBankruptcyPetition>N</isBankruptcyPetition>
        <isTrusteeApointed>N</isTrusteeApointed>
        <isBondRevoked>N</isBondRevoked>
      </financialDisclosure>
      <judgmentLienDisclosure>
        <isLienAgainst>N</isLienAgainst>
      </judgmentLienDisclosure>
    </disclosureQuestions>
    <signatureInfo>
      <com:signature>
        <com:dateSigned>04-20-2020</com:dateSigned>
        <com:signature>Gregory S. Byer</com:signature>
        <com:title>Chief Compliance Officer</com:title>
      </com:signature>
    </signatureInfo>
  </formData>
</edgarSubmission>
