The authors analyse a series of 138 cases of complicated diverticular sigmoiditis treated surgically. They noted 50% of pyostercoral peritonitis, 32% of persigmoid abscesses, 13% of case of intestinal obstruction, and 5% of cases of fistual or hemorrhage. The overall mortality was 28% and depended mainly more on the surgical management adopted than on the type of complication. In this respect, simple colostomy with drainage of the septic focus had a mortality of 18%. The results suggest surgical operation in two stages, in the form of colonic resection, with, depending on each case, an anastomosis straight away with transverse colostomy or segmental colectomy with bitubular colostomy (Mikulicz procedure) or, in rarer cases, simple colostomy. The authors emphasise the interest of early surgery in sigmoiditis with complications and contrast the mortality of cold surgery which is now about 5% compared with 28% in emergency cases with complications.