A 67-year-old patient with upper gastrointestinal bleeding. HISTORY AND CLINICAL FINDINGS: A 67-year old patient with melaena and anaemia (haemoglobin 4.8 g/dl) for 14 days had been admitted to hospital under suspicion of upper gastrointestinal bleeding. The patient had a history of 2/3 resection of the stomach for recurrent duodenal ulcer and of a right nephrectomie for hypernephroma 18 years ago. There was no abdominal pain on pressure, nor muscular guarding. INVESTIGATIONS: Endoscopy (oesophago-duodenoscopie, coloscopie), radiography (angiography, gastrografin passage) and ultrasound failed to locate the source of bleeding. TREATMENT AND COURSE: After repeated endoscopic attempts to localize the source of bleeding and growing need of transfusions (12 blood-concentrates in 5 days) an exploratory laparotomie was done. Surprisingly a bleeding fistula between the stump of the right renal arteria and duodenum was found. The defects were excised and directly closed. CONCLUSIONS: Secondary aortoduodenal fistula after nephrectomy is rare. If the source of bleeding can't be found, and there is in any doubt an exploratory laparotomy should be done.