Tumors of the minor papilla of the duodenum are quite rare. We report the first documented case of an adenoma of the minor papilla complicating pancreas divisum. A 52-year-old woman was admitted to our hospital for treatment of an asymptomatic duodenal tumor detected by computed tomography scan. Endoscopy showed an 18-mm, whitish-colored, sessile mass located in the descending duodenum proximal to a normal appearing major papilla. Endoscopic retrograde pancreatography revealed divisum of the pancreas with dilatation of pancreatic duct ranged in the dorsal pancreas. Transduodenal minor papillectomy was performed because there is malignant potential of the tumor and the possibility of acute pancreatitis. The Santorini orifice was then re-approximated to the duodenal wall for protection against acute pancreatitis caused by scarring and stenosis of the duct orifice as a possible late complication. The patient's postoperative course was uneventful and she has been asymptomatic without evidence of tumor recurrence or stenosis of the Santorini orifice on endoscopic examination for the last 4 years.