Better knowledge of independent risk factors might decrease mortality and morbidity rates following colorectal surgery. Prospective multicenter study. From June to September 2002, consecutive patients undergoing open or laparoscopic surgery (electively or on an emergent basis) for colorectal cancers or diverticular disease were prospectively included. Exclusion criteria were colectomy for other causes (eg, inflammatory bowel diseases, benign polyps). The structured sheet of data collection included more than 200 items on all perioperative data concerning the patient, the disease, and the operating surgeons. Postoperative mortality and morbidity were defined as in-hospital death and complications. Among 1421 patients, the in-hospital death rate was 3.4% and the overall morbidity rate was 35%. Four independent preoperative risk factors of mortality were found: emergency surgery, loss of more than 10% of weight, neurological comorbidity, and age older than 70 years. Six independent risk factors of morbidity were found: age older than 70 years, neurologic comorbidity, hypoalbuminemia, cardiorespiratory comorbidity, long duration of operation, and peritoneal contamination. Colorectal resection in France is associated with a 3.4% mortality rate and a 35% morbidity rate. Knowledge of the risk factors could help surgeons manage cases.