We report the rare case of a large adenoma of Brunner's glands as the cause of an upper gastrointestinal hemorrhage. Endoscopic resection is the therapy of choice in the appropriate setting. An unequivocal histological diagnosis by forceps biopsy often is not possible; there are no clear cut endoscopic criteria. The development of complications especially of severe hemorrhage increases with diameter of the adenoma. Therefore, the complete excision either endoscopically or by surgery should be attempted.