SummaryApproximately 17 per cent of 500 patients with diverticular disease had colonic hemorrhage. In most cases the bleeding was mild, but it is potentially a lethal complication. In this series the associated mortality was 3.6 per cent. If the bleeding site is readily identifiable it is reasonable to resect the involved area; if not, total abdominal colectomy with ileorectal anastomosis is the preferred procedure. Selective arteriography is now performed more often, and has been helpful in localizing the site of hemorrhage in several patients.