A 50-year-old man was admitted to our hospital with a chief complaint of melena. An emergency upper gastrointestinal endoscopic study revealed arterial bleeding from a duodenal submucosal tumor, 1.5cm in diameter and about 2cm in an oral direction from the papilla of Vater. Because it was not possible to stop the bleeding, an emergency resection of the tumor was performed. Macroscopically, the ulcerated tumor was approximately 1.5cm in diameter. Histopathologically, the tumor was determined to be located in the accessory papilla of the duodenum. We report here a rare case of bleeding from the accessory duodenal papilla and discuss the literature.