The present paper describes the presentation and management of 9 patients who developed dilatation in the colon during the course of spontaneous ischaemic colitis. The length of history varied from 16 hours to 6 weeks. The patients usually had diarrhoea and abdominal pain but no bleeding and posed a difficult diagnostic problem. At laparotomy, three distinct types of colonic dilatation were recognised. Dilatation of non-diseased colon proximal to localised ischaemic segments occurred in 2 patients, 3 patients exhibited dilatation of obviously gangrenous colon, 4 patients showed dilatation of ischaemic but possibly viable colon, yet in 1 of these, multiple sealed perforations were present. Resection of the obvious or possibly gangrenous colon was the treatment used but in the 2 patients with dilatation due to stricture, transverse colostomy alone was employed.