This is a report of the first case of adenocarcinoma arising in an ileal pouch after proctocolectomy for ulcerative colitis in a patient who had also undergone orthotopic liver transplantation for primary sclerosing cholangitis. Previously reported cases of adenocarcinoma developing after formation of an ileoanal pouch are reviewed as is the evidence for neoplastic transformation of the ileal mucosa. The risk factors for the development of colorectal cancer in patients with ulcerative colitis and the possibility that these may be risk factors for the development of pouch malignancy are discussed. We conclude that this patient exemplifies a small group of patients who may be at increased risk of developing pouch malignancy and need endoscopic follow-up. There is also the need for longer-term follow-up data to determine the risk of this rare and potentially devastating complication of restorative proctocolectomy.