The authors present a case of a 78-year-old female patient who was initially examined at the cardiology department for consideration of pacemaker implantation. An upper GI endoscopy was performed due to anemia and melena and a large duodenal diverticulum was identified. Consequently, signs of acute abdomen developed and further examinations confirmed diverticular perforation. As an emergency surgical resection of the diverticulum was performed and the patients recovered uneventfully. In this case report the authors discuss the management of the above condition as well as literature review is performed.