Objectives: To better understand the time-course in which major complications occur after radical cystectomy and to describe associations with complications at 30 and 90 days. Methods: A database of radical cystectomy cases was queried for preoperative, perioperative, and postoperative data. Follow-up extended to 90 days postsurgery and included major complications (Clavien III-V). Early (30-day) and late (90-day) complication rates were compared via McNemar's test, and patient characteristics were compared across complication time groups by one-way ANOVA or Fisher's exact tests. Multinomial logistic regression was used to explore associations between patient characteristics and complication timing. Results: Of 969 patients undergoing radical cystectomy, 210/969 (21.7%) experienced a complication within 90 days. The rate of major complication significantly differed at 30 and 90 days (14.4% [conflict of interest (CI): 12.4%-16.9%] vs 21.7% [CI: 19.2%-24.4%] respectively, P ≤.0001). Chronic obstructive pulmonary disease (COPD) (P = .03), Charlson Comorbidity Index (P = .02), and Indiana pouch diversion (P = .002) were significant predictors of early complication. Diabetes was the strongest predictor for late complication (OR: 2.42; P = 0.01). Diabetes was also a significant predictor for late genitourinary complications (OR 3.39; P = .01), and smoking history was a significant predictor for late infectious complications (OR 3.61; P = .01). Conclusion: We identified a significant number of complications occurring after 30 days postcystectomy, including the majority of deaths and genitourinary complications. These findings suggest that assessment of complications exclusively at 30 days would fail to capture a large proportion of major complications and deaths. Understanding the time-course of complications postcystectomy will serve to better inform design of future outcome studies.