Résumé : Objectives: To report the perioperative events after radical cystectomy and urinary diversion in bladder cancer in terms of major and minor complications and to seek statistical relationships with patient's characteristics and surgical procedures. Methods: One hundred and sixty-one radical cystectomies performed in the modern era in two academic hospitals were reviewed. Preoperative patients characteristics (age, sex, hemoglobin, total protein, weight and height) and perioperative data (operative time, type of urinary diversion, associated procedures, blood transfusion, seniority of the surgeon) were recorded. Perioperative morbidity was defined by any adverse event during hospital stay or within 30 days after surgery, those requesting an additional stay of more that 3 days in the intensive care unit or a reoperation being classified as major complications. Significant relationships were sought for classes by Student's t test for comparison of quantitative variables and Yate's corrected χ2 test for categorical variables. Spearman's rank correlation test was used for comparison of quantitative variables. Results: Major complications were observed in 41 patients (25.5%) and resulted in 14 reoperations (8.7% reoperation rate). Most of them were diversion-related and were statistically related to the ASA score ≥3 (p < 0.01, 5.7 odds ratio). Compared to sophisticated means of diversion, cutaneous diversion resulted in minimal operative time and hospital stay. No relationships between age, body mass index, biological parameters, type of diversion, associated procedure, surgeon's experience and postoperative complications could be evidenced. Uneventful recovery resulted in a 16.6 days mean hospital stay, minor complications induced a significant 3.8 days additional stay and major complications resulted in major lengthening of hospital stay (21.2 days mean additional stay). Conclusion: ASA scores equal to or greater than 3 were associated with major complications and most specially those related to the type of urinary diversion. Therefore, we recommend special care in the selection of the type of urinary diversion and further preoperative evaluation inclusive of nutritional assessment. Copyright © 2001 S. Karger AG, Basel.