A rare form of tetralogy of Fallot, in which large ventricular septal defect was located at subpulmonary position rather than beneath a well developed crista supraventricularis was operated in this Department. This case satisfied the criteria for the diagnosis of tetralogy of Fallot, having large ventricular septal defect beneath the aortic valve with overriding of aorta, pulmonary stenosis and right ventricular hypeFtrophy. The operation was done through a median sternotomy using cardiopulmonary bypass. A vertical right ventriculotomy was extended to the pulmonary valve ring. Pulmonary and aortic valve were adjacent to each other, in contrast to the situation of classic tetralogy of Fallot. Pulmonary valvulotomy was done and ventricular septal defect was closed. with Teflon, and right ventricular outflow tract was reconstructed with woven Dacron covered by pericardial patch after minimal resection of septal band. The post-operatiove courses was uneventful except wound infection. The patient was discharged 15 days after open heart surgery.