OBJECTIVE Surgery for colorectal radiation injury is technically difficult and often followed by complications. This study evaluates factors affecting outcome. METHODS A retrospective 30-year review was carried out. Preoperative characteristics and operative variables were correlated with morbidity, mortality, and success in providing symptomatic relief. RESULTS A total of 60 cases and 75 colon and rectal lesions were analyzed. After surgery, the morbidity rate was 65 percent, and the mortality was 6.7 percent. A successful outcome in providing symptomatic relief was achieved in 71.7 percent of cases. When comparing success after operations for the different lesions (stricture, 78.1 percent; hemorrhage, 64.3 percent; perforation, 100 percent; and fistula, 54.5 percent), the presence of a fistula was associated with symptomatic relief significantly less often than the remainder (P = 0.03). The type of operation had no effect on success rate: 72 percent for diversion, 66.7 percent for resection, and 83.3 percent for bypass. Morbidity and mortality rates were not significantly influenced by site of lesions, type of lesions, or choice of surgical operation. A permanent stoma was necessary in 70 percent of patients. CONCLUSIONS The morbidity for surgical treatment of large bowel radiation injury is substantial, and largely unrelated to the type and location of the radiation lesion, as well as the type of operation. Success rates are reasonably high, but worst after fistula repair. The selection of therapy (medical, endoscopic, surgical) for radiation-induced colorectal lesions must take into account numerous factors and be highly individualized.