An 18-day-old male neonate with hypoplastic left heart syndrome underwent surgical intervention by modification of the Norwood procedure on September 23, 1986. Hypoplastic left heart syndrome is a serious congenital cardiac anomaly that has a fatal outlook if left untreated. Included in this anomaly are [1] aortic valve atresia, and hypoplasia of the ascending aorta and aortic arch, [1] mitral valve atresia or hypoplasia, and [3] diminutive or absent left ventricle. Patent ductus arteriosus is essential for any survival, and there is usually a patent foramen ovale. Coarctation of the aorta is frequently associated with the lesion.z With a limited period of cardiopulmonary bypass, deep hypothermia, and circulatory arrest, the ductus arteriosus was excised. The main pulmonary artery was divided immediately below its branches, and the distal stump of the divided pulmonary artery was closed with a pericardial patch. The aortic arch was incised, and a 1 5mm tubular Dacron prosthesis was inserted between the main pulmonary artery and the aortic arch. A 4mm shunt of polytetrafluoroethylene graft was established between the new ascending aorta and the right pulmonary artery to provide controlled pulmonary blood flow. Following rewarming, the heart started to beat regularly, but the patient could not be weaned from cardiopulmonary bypass. At autopsy, the patient was found to have hypoplasia of the aortic tract complex with mitral atresia and aortic atresia. A secundum atrial septal defect was noted. Right atrial and ventricular hypertrophy was present, and the left ventricle was entirely absent. Although unsuccessful in this case report, continuing experience with hypoplastic left heart syndrome will lead to an improvement in result.