These fistulae are very rare: 8 to 11 p. 100 of all coronary fistulae. Three types are recognised: right coronaro-ventricular, left coronaro-ventricular, and coronao-pulmonary. The two first types are found most frequently in association with a sigmoid atresia on the orifice, and with ventricular hypoplasia in the presence of a functional atrio-ventricular valve. The fistula then serves as a means of ventricular ejection. Of the secondary fistulae, the right coronaro-ventricular type is the most common (73 p. 100). The authors have found 30 cases in the published literature, and add 2 of their own. They have also reviewed the clinical features and the findings on coronary arteriography and post mortem studies on such fistulae. They discuss their etiology, pathogenesis, and physiopathology. Surgical correction involves repairing the fistula in one stage. Fistulae of the left coronaro-ventricular type are exceptions to this rule (9 p. 100), as they are always associated with a rapidly fatal hypoplasia of the left side of the heart. Coronaro-pulmonary fistulae (18 p. 100) are usually found in association with extreme forms of Fallot's tetralogy, and a relatively simple surgical correction can form part of the total correction of the tetralogy.