Abstract Context and Objectives Urinary bladder paraganglioma (UBPGL) is rare. We aimed to characterize the presentation and outcomes of patients diagnosed with UBPGL. Methods We conducted a multi-center study of consecutive patients with pathologically-confirmed UBPGL evaluated between 1971 and 2021. Outcomes included repeat bladder surgery, metastases, and disease-specific mortality. Results 110 patients (56, 51% women) were diagnosed with UBPGL at a median age of 50 years (IQR, 36-61 years). Median tumor size was 2 cm (IQR, 1-4 cm). UBPGL was diagnosed prior to biopsy in only 37 (34%), and only 69 (63%) patients had evaluation for catecholamine excess. In addition to the initial bladder surgery, 26 (25%) required multiple therapies, including repeat surgery in 10 (9%). Synchronous metastases were present in 9 (8%) patients, and 24 (22%) other patients with UBPGL developed metachronous metastases at a median of 4 years (IQR, 2-10 years) after initial diagnosis. Development of metachronous metastases was associated with younger age (Hazard ratio, HR 0.97, 95%CI 0.94-0.99), UBPGL size (HR of 1.69, 95%CI of 1.31-2.17), and a higher degree of catecholamine excess (HR of 5.48, 95%CI of 1.40-21.39). Disease-specific mortality was higher in patients with synchronous metastases (HR of 20.80, 95%CI, 1.30-332.91). Choice of initial surgery, genetic association, sex, or presence of muscular involvement on pathology were not associated with development of metastases or mortality. Conclusions Only a minority of patients were diagnosed before biopsy/surgery, reflecting the need of better diagnostic strategies. All patients with UBPGL should be monitored life-long for development of recurrence and metastases. Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m., Monday, June 13, 2022 12:48 p.m. - 12:53 p.m.