Primary aortoesophageal fistula, an abnormal communication between native aorta and oesophagus, is an extremely rare cause of upper gastrointestinal bleeding. The typical symptoms, known as the Chiari´s triad, are only present in 45% of cases. It has a high mortality, so early diagnosis is essential to increase the probability of survival. We present a case report of a patient with massive upper gastrointestinal bleeding due to primary aortoesophageal fistula.