One of the serious complications of diverticulitis eventually develops in 25 to 30 per cent of patients with this disease. The use of the multiple-stage procedure for these complications has considerably reduced surgical mortality, but morbidity remains high. To reduce the surgical morbidity in diverticulitis, inadequate operative procedures should be avoided. However, a more effective method is to operate on patients likely to have obstruction or perforation before these serious complications develop. A one stage procedure can then be safely used. Inability to exclude carcinoma is also an imperative indication for surgery in patients with diverticulitis.