Abstract From 1966 to 1987, 177 consecutive patients were operated on electively for diverticular disease of the sigmoid colon. The indications for surgery were: colovesical fistula (n = 12), suspicion of residual abscess (n = 39), two or more previous attacks of acute inflammation (n = 52), chronic symptoms (n = 72) and suspicion of carcinoma (n = 2). An abscess was found at operation in 76 patients (43 per cent) and this was extracolic with local peritonitis in 5 2 patients (29 per cent). An unsuspected abscess was found in 25 of the 72 patients operated on for chronic symptoms. Colonic resection with primary anastomosis was performed in 95 per cent of the 177 patients and in 94 per cent of those 52 patients with an extracolic abscess. There were no postoperative deaths and no clinical anastomotic leakages. Long-term results were very good in 85 per cent of the 177 patients and in 82 per cent of the 72 patients operated on for chronic symptoms. The results of this series suggest that a one-stage procedure can be safely performed with some technical precautions in most patients operated on electively for diverticular disease, even if an extracolic abscess is found. The good long-term results in patients operated on for chronic symptoms suggest that such symptoms should be taken into account with respect to surgical indications.