Between 1978 and 1988, 12 patients with familial adenomatous polyposis (FAP) and severe duodenal polyposis underwent duodenotomy and duodenal polypectomy. The patients were from two separate institutions; all were women, with a mean age of 45.6 (range 25-62) years at the time of duodenotomy. Recurrent duodenal polyposis was detected at endoscopy in all 12 patients, at a mean of 13.3 (range 5-36) months after duodenotomy. All patients had moderate to severe duodenal polyposis at the time of the last endoscopic examination. Local excision of duodenal adenomas is an unsatisfactory treatment option in those with FAP. The ideal management of patients with FAP who have severe duodenal polyposis remains uncertain.