From 1978 to 1993, 220 patients were admitted at the Cl. Chirurgica III of the University of Bologna because of acute colonic diverticulitis. During the same period 108 patients (58 females and 50 males; mean age 65 years) were operated on for complications of the disease; 21 acute diverticulitis, 10 pericolic or pelvic abscess, 30 purulent peritonitis, 7 fecal peritonitis, 19 obstruction, 14 hemorrhage and 7 fistula. Surgical techniques were: resection and primary anastomosis (n. = 46), two or three stage procedure (n. = 49), Hartmann's resection (n. = 13). Mortality rate was 15%, 14,2% and 7,6% respectively. The advantages or disadvantages of the various surgical approaches in relation to the type of complications were evaluated. In conclusion appropriate segmental resection of the colon with or without primary anastomosis is recommended.