Patients with familial adenomatous polyposis (FAP) are at increased risk for the development of periampullary cancer. The aim of this study was to evaluate the roles of endoscopic and surgical therapy in the management of advanced duodenal polyposis in FAP. From 1990 to 1995, seventy-four FAP patients were enrolled in a prospective endoscopic surveillance protocol. Among these, 11 (14.8%) developed advanced duodenal polyposis and one had duodenal adenocarcinoma. Six patients underwent endoscopic resection of duodenal (n=5) or ampullary adenomas (n=1). The following operations were performed in the remaining six patients: ampullectomy in four, open polypectomy in one, and a Whipple procedure in one. There was one patient who died of acute pancreatitis following endoscopic ampullectomy. The patient with invasive duodenal cancer died of local recurrence. Small polyps were observed at the site of previous resection in all (9 of 9) patients undergoing repeat endoscopy during a mean follow-up of 18 months (range 4 to 34 months). An endoscopic and local surgical resectional approach to advanced duodenal polyposis in FAP is fraught with high recurrence rates, although recurrent polyps are small and may be amenable to retreatment in the future. Long-term follow-up is necessary to prove that deaths from duodenal or ampullary cancer are prevented with this strategy.