['We assessed the prognostic value of pT3 bladder urothelial carcinoma substaging.', 'We reviewed the records of 2,605 patients treated with radical cystectomy for bladder urothelial carcinoma at 6 international centers, of whom 808 (31.0%) had pT3 disease. No patient received systemic chemotherapy or radiotherapy preoperatively. Median followup was 45 months in survivors at last followup.', 'Median patient age was 68 years. Stage was pT3a in 310 patients (38.4%) and pT3b in 498 (61.6%). Of the patients 352 (43.6%) had metastasis to regional lymph nodes. Five-year recurrence-free (43.8% and 41.4%) and cancer specific (48.6% and 46.8%) survival estimates were similar in pT3a and pT3b cases (p = 0.277 and 0.625, respectively). Conversely in patients with pathologically negative lymph nodes pT3b substaging was associated with worse 5-year recurrence-free (60.7% vs 47.9%) and cancer specific (64.4% vs 55.0%) survival (p = 0.020 vs 0.048).'] Is pT3 Substaging a prognostic indicator for lymph node negative urothelial carcinoma of the bladder?