Aortoventricular fistula, a rare congenital or acquired defect of the aortic wall, is characterized by an abnormal connection between the aorta and one of the ventricles. Symptom severity correlates with the diameter of the fistula and with the acute or chronic timing of presentation. The diagnosis is usually made by using echocardiography, and surgical treatment is necessary to avoid progression to heart failure. We describe the case of a 27-year-old woman who underwent successful surgical repair of an aortoventricular fistula that originated from the right coronary sinus and extended into the left ventricle through the interventricular septum. In addition to the patient's case, we briefly discuss this unusual condition