Introduction: There is no consensus on the appropriateness of local resection in the treatment of ampullary tumors, because local resection of apparently benign tumors is occasionally followed by incurable malignant recurrence. We analyzed the results of local resection of 30 ampullary tumors whose preoperative diagnosis was benign adenoma. Methods: There were17 men and 13 women (mean age 65 years) who had transduodenal local resection of ampullary tumors at UCSF Medical Center between1992-2004. Frozen section pathologic examination was obtained in 80% of cases. The patients were followed for a mean of 5.6 years. Results: Preoperative biopsies (obtained in all patients) were reported as follows: 18 adenoma; 5 adenoma with dysplasia; 5 adenoma with atypia; and 2 with no malignant cells. The final pathology report showed 23 villous adenomas, 6 adenocarcinomas and 1 paraganglioma. Among the 6 with a final diagnosis of cancer, the preoperative biopsy in 5 cases was adenoma with dysplasia and in one was adenoma with cellular atypia. There were 3 (13%) recurrences among the 23 adenomas, all in the form of benign adenomas. The mean time to recurrence was 3.2 years. One of these 3 cases had a positive margin at the time of resection. Two recurrences were treated with Whipple resection and the other with endoscopic snare polypectomy. There were 2 recurrences among the 6 adenocarcinomas (33%), with a mean time to recurrence of 4.4 years. Both cases had negative margins at the time of the initial resection. At the time of recurrence, liver metastases were present in one case and the other was unresectable. Tumor size did not influence the recurrence rate. There were six tumors with positive margins on permanent section and only one recurred (adenoma). Conclusions: Ampullary tumors that show evidence of carcinoma or dysplasia on preoperative biopsy should be treated with pancreaticoduodenectomy, since they are likely to harbor malignancy. Recurrence after local resection of malignant lesions is too high for this to be considered a reasonable alternative to a Whipple procedure. Ampullary adenomas can be resected locally with good results, but the recurrence rate was 13% even with negative margins, so endoscopic surveillance is indicated postoperatively. No adenomas recurred as carcinomas, suggesting that local resection, when technically feasible, is acceptable for benign ampullary adenomas without dysplasia or atypia on preoperative biopsy.