A fistula from the left aortic sinus to the left ventricle is reported that was successfully repaired using cardiopulmonary bypass. In addition, 175 cases of fistula to the heart from the aortic sinuses published in the English literature from 1839 through 1972 were studied, with particular emphasis on the 126 patients who underwent operative repair. The major cause of the fistulas (76%) was found to be rupture of a congenital aortic sinus aneurysm, usually during the third or fourth decade of life. The remainder of these fistulas to the heart consisted of simply a tract in an otherwise normal sinus. Ventricular septal defect was the most common associated defect and, when present, was nearly always related to a fistula arising from the right aortic sinus. Repair was successful in 86% of the 126 operated patients. The principles of operative treatment of these fistulas are reviewed.