Objective: Paragangliomas of the urinary bladder (UBPGLs) are rare neuroendocrine tumours and pose a diagnostic and surgical challenge. It remains unclear what factors contribute to a timely presurgical diagnosis. The purpose of this study is to identify factors contributing to missing the diagnosis of UBPGLs before surgery. Design, Patients and Measurements: A total of 73 patients from 11 centres in China, and 51 patients from 6 centres in Europe and 1 center in the United States were included. Clinical, surgical and genetic data were collected and compared in patients diagnosed before versus after surgery. Logistic regression analysis was used to identify clinical factors associated with initiation of presurgical biochemical testing. Results: Among all patients, only 47.6% were diagnosed before surgery. These patients were younger (34.0 vs. 54.0 years, p <.001), had larger tumours (2.9 vs. 1.8 cm, p <.001), and more had a SDHB pathogenic variant (54.7% vs. 11.9%, p <.001) than those diagnosed after surgery. Patients with presurgical diagnosis presented with more micturition spells (39.7% vs. 15.9%, p =.003), hypertension (50.0% vs. 31.7%, p =.041) and catecholamine-related symptoms (37.9% vs. 17.5%, p =.012). Multivariable logistic analysis revealed that presence of younger age (<35 years, odds ratio [OR] = 6.47, p =.013), micturition spells (OR = 6.79, p =.007), hypertension (OR = 3.98, p =.011), and sweating (OR = 41.72, p =.013) increased the probability of initiating presurgical biochemical testing. Conclusions: Most patients with UBPGL are diagnosed after surgery. Young age, hypertension, micturition spells and sweating are clues in assisting to initiate early biochemical testing and thus may establish a timely presurgical diagnosis.