During the eight-year-period from 1968 to 1975 14 patients have been operated on because of ulcerative colitis. A severe, or fulminant, colitis attack was the cause in 48 of these. Most of these patients had been referred from other hospitals. Eight died, six having had a bowel perforation prior to operation, the others having received protracted conservative treatment and came to operation very late. Five of the patients were more than 58 years old. The indications for elective operations were chronic severe symptoms and/or risk of malignant change. In a conservatively treated patient material and with total involvement of their colitis, the cumulative risk of cancer after 30 years follow-up was over 35%. The mortaility in elective surgery was 3%; are all patients up to 1977 included the mortaility is less than 2%. Ileo-rectoanastomoses gave very poor long-term results. Patients with an ileostomy have shown themselves to be well adjusted both socially and psychologically. There are, however, some risk of sexual disturbances.