We reported the case of a 68-year old male with chest pain. The coronary angiography showed the disease of the left anterior descending coronary artery and, incidentally, an arteriovenous coronary fistula between this coronary branch and the pulmonary artery. The patient underwent off-pump coronary bypass through a left mini thoracotomy. In the present case, after a series of detailed exams, we decided not to close the fistula for several reasons, but mainly because of the singular localization of an atherosclerotic plaque proximal to the origin of the fistula. Therefore, under specific conditions, it may not always be mandatory to close the coronary arteriovenous fistulas.