To evaluate the association of ABO blood type with clinicopathologic outcomes and mortality among patients with urothelial carcinoma of the bladder treated with radical cystectomy (RC).We identified 2,086 consecutive patients who underwent RC between 1980 and 2008. Postoperative recurrence-free survival (RFS) and cancer-specific survival (CSS) were estimated using the Kaplan Meier method and compared with the log-rank test. Cox proportional hazards regression models were used to evaluate the association of ABO blood type with outcomes.A total of 913 (44%), 881 (42%), 216 (10%), and 76 (4%) patients had blood type O, A, B, and AB, respectively. Median postoperative follow-up among survivors was 11.0 years (interquartile range: 7.7-15.9y). Overall, 1,561 patients died, with 770 deaths attributable to bladder cancer. Non-O blood type was associated with significantly worse 5-year RFS (65% vs. 69%; P = 0.04) and/or CSS (64% vs. 70%; P = 0.02). In particular, among patients with≤pT2N0 disease, the 5-year RFS for those with non-O vs. O blood type was 75% vs. 82%, respectively (P = 0.002), whereas the 5-year CSS was 77% vs. 85%, respectively (P = 0.001). Moreover, on multivariable analysis, blood type A remained independently associated with an increased risk of cancer-specific mortality (hazard ratio = 1.22; P = 0.01).Non-O blood type, particularly blood type A, is associated with a significantly increased risk of death from bladder cancer among patients undergoing RC. If validated, the utility of a multimodal therapy approach, including perioperative chemotherapy, or more frequent postoperative surveillance in this cohort warrants further study.