We report here on a 44-year-old previously healthy patient with a two-year history of intermittent upper abdominal pain. In the outpatient gastroduodenoscopy and X- ray examinations of the small intestine an intraluminal duodenal diverticulum was suspected. Clinical examination and laboratory tests did not show any abnormal findings. In order to exclude other causes for the patient's complaints coloscopy, ERP and MRCP were performed. The latter was done because the bile duct could not be intubated in the ERCP due to the altered anatomy. By use of endoscopic ultrasound a mucosal duplication was demonstrated and thus the diagnosis confirmed. Subsequently, the diverticulum sac was sliced by argon plasma coagulation. The postinterventional course was without complications and the patient was without symptoms afterwards. The intraluminal duodenal diverticulum is a rare differential diagnosis of pain in the upper abdomen. The diverticulum should be endoscopically removed if other causes for abdominal pain have been ruled out and possibly associated malformations have been excluded.