Clinical differentiation between acute myocardial infarction and peptic ulcer perforation may sometimes be difficult. We report on a sixty-five year-old patient who presented at the Emergency Department with upper abdominal pain and local tenderness suggestive of acute perforation of a gastric ulcer. However, the initial electrocardiogram (ECG) showed acute inferior wall myocardial infarction. Although abdominal pain is a major symptom of acute inferior wall myocardial infarction the history of gastritis and abdominal findings on admission of our patient required further exploration. The first plain abdominal radiograph was inconspicuous, therefore we performed a gastroscopy, which showed a prepyloric gastric ulcer. The second plain abdominal radiograph revealed air in the peritoneal cavity as sign of perforation. Echocardiography, ECG and the increase of heart enzymes confirmed acute inferior wall infarction. After successful surgical treatment of the perforated ulcer the patient recovered and progressed satisfactorily at the intensive care unit. He was discharged after three weeks and remains in good health. This case shows that rapid diagnosis and good interdisciplinary therapeutic management prevented a fatal outcome of acute myocardial infarction and concomitant gastric ulcer perforation in an elderly patient.