The authors describe their experience with three cases of toxic megacolon: two cases were complications of an ulcerative colitis and died after surgery; one case was a complication of Crohn's disease and recovered after medical resuscitation treatment. Diagnosis was based on clinical features and direct abdominal X-ray showing an evident dilatation of the colon. The authors think that intense medical treatment has to be carried out in all cases without urgent surgical indication: even if not always successful, a medical therapy will be an appropriate preparation for operation. The authors believe that the operation of choice is colectomy with ileo-rectal anastomosis plus upstream protective ileostomy or right terminal ileostomy plus left iliac sigmoidostomy with subsequent reconstruction of continuity.