Background: The myeloproliferative neoplasms (MPNs) are a rare hematologic malignancy with significant symptom burden. Disease-related registries can be a useful and important tool for rare disease research and surveillance. Aims: The MPN research foundation steering committee aimed to create a prospective patient-reported MPN registry to capture demographics, disease related events, and symptom burden. Methods: Using the Genetic Alliance platform, an online registry was created which assessed MPN patients’ baseline demographics and disease history with prospective patient-reported disease events and symptom burden. 50 MPN patients assisted with registry beta testing. Survey registration information was disseminated among multiple MPN-related websites. Results:Accrual: A total of 454 MPN patients initiated the online registry process. Of these, 355 individuals completed introductory demographic and disease information. Respondents were predominantly female (63.7%). Disease-related information: The disease distribution of participants included 45% with essential thrombocythemia, 39% with polycythemia vera, and 12% with myelofibrosis. Most frequent therapies included aspirin (75.5%), hydroxyurea (42.1%), JAK inhibitor (17.6%), or no therapies (9.9%). To date, 436 surveys were logged reporting 902 disease events by 303 users (Table 1). Disease Symptom Burden: At the time of data analysis, 250 participants completed a 418 MPN10 symptom surveys. Mean MPN10 score was 1.9 for ET, 2.3 for PV, and 1.9 for MF. Conclusions: An MPN patient registry has the capabilities of addressing key critical questions regarding MPN patient symptom and treatment needs. Its dynamic nature allows researchers and patient advocates to prospectively connect with individual patients regarding additional information and unmet needs in this rare population.Table 1.