Background: Cancer and immobility both contribute to the development of venous thromboembolic events (VTE), including pulmonary embolism and deep vein thrombosis. As such, patients undergoing radical cystectomy for bladder cancer are at elevated risk. We sought to assess the long-term incidence of VTE among all patients undergoing radical cystectomy in the province of Ontario. Methods: We conducted a population-based cohort study to examine the incidence of VTE, a composite of pulmonary embolism and deep vein thrombosis, among all patients treated with radical cystectomy for bladder cancer between 2002 and 2014 in Ontario, Canada. We estimated the cumulative incidence of VTE and used Fine and Grey competing risk survival analysis to assess risk factors for VTE while accounting for the risk of any cause mortality. Results: Among 3623 eligible patients, the 10 year cumulative incidence of VTE was 6.68% (Table 1). Among those who experienced VTE, the median time from surgery was 216 days (interquartile range 52-677 days; mean 527 days). However, VTE rates peaked much earlier with a mode of 20 days. Neither preoperative (HR 0.68, 95% CI 0.39-1.18) nor postoperative chemotherapy (HR 1.32, 95% CI 0.95-1.84) were significantly associated with VTE incidence. While patients with a prior history of VTE had increased risk of VTE after cystectomy (HR 5.1, 95% CI 2.2-12.0), age, gender, comorbidity score, rurality, diversion type (continent vs ileal conduit), treatment at an academic institution, or year of treatment were not significantly associated with the risk of VTE. Conclusions: Among patients undergoing cystectomy for bladder cancer, the cumulative incidence of VTE continues to rise long after the date of surgery indicating that previous studies may have underestimated these rates, but the highest rates occur at 20 days after surgery. Chemotherapy does not appear to increase the risk of VTE.