Primary resection with colostomy has been widely adopted during the past decade for the treatment of patients with severe complications of diverticulitis. Because of this, a retrospective review was performed of all patients undergoing surgery for colonic diverticular disease during the two time periods 1974 to 1978 (n = 196) and 1982 to 1986 (n = 230). Forty-three patients had abscess or peritonitis from 1974 to 1978, whereas 52 had these complications from 1982 to 1986. Colostomy and drainage alone were used for 31 of 43 patients (72%) from 1974 to 1978, while primary resection with colostomy was used for 39 of 52 patients (75%) from 1982 to 1986 (p less than or equal to 0.5). Despite this shift in treatment method, mortality increased from 14% in 1974 to 1978 to 19% in 1982 to 1986 (p = NS). Patients with peritonitis had identical mortalities (22%) during both intervals. Patients with abscess experienced an increase in mortality from 8% in 1974 to 1978 to 15% in 1982 to 1986 (p = NS). The widespread use of primary resection for patients with severe complications of diverticulitis appears not to have altered mortality for those with diffuse peritonitis and may have worsened the outcome for those with abscess.