Though surgical resection has been the traditional treatment for tumors of the ampulla of Vater, endoscopic maneuvers such as snare resection, laser photodestruction and electrofulguration have recently been introduced to avoid operation-related morbidity and mortality. From 1994 to 1996, 6 patients with ampullary tumor were managed by endoscopic snare resection and regularly followed. Endoscopic snare resection of the ampullary tumor was technically feasible in all patients and each procedure was performed in a single session. Histologic diagnoses of the resected specimens were adenoma in 4 patients and adenoma with coexistent adenocarcinoma in 2 patients. Resection margins were negative in all patients except 1 with coexistent adenocarcinoma and a radical pancreaticoduodenectomy was performed in that case. For the other patient with adenocarcinoma foci, no further treatment was persued since he was 72-year-old and refused operation. Acute pancreatitis developed in 2 patients after endoscopic therapy, but was resolved with conservative management. There was no procedure-related death. Surveillance duodenoscopy performed at 1 and 6 months after endoscopic resection revealed no evidence of recurrent tumor in 4 patients with adenoma. Among them, 3 patients are alive without evidence of recurrence at 16-37 months after resection, but 1 patient was lost after 9 months of follow-up. The patient with adenocarcinoma in whom a pancreaticoduodenectomy was performed, has been alive without recurrence for 12 months. Oral 5-fluorouracil was administered for the other patient with adenocarcinoma foci. Though he experienced local recurrence at 13 months after the procedure, he has been alive for 28 months after resection. In conclusion, endoscopic snare resection may be applied as a viable alternative to surgery in selected patients with small ampullary tumors.