A new palliative surgical procedure for interruption of the aortic arch was successfully performed in an infant. A Teflon graft was inserted from the main pulmonary artery to the descending thoracic aorta in order to bypass a stenotic ductus arteriosus, and both pulmonary artery branches were banded to reduce the pulmonary blood flow.This procedure may also prove life-saving in the hypoplastic left heart syndrome, with the addition of atrial septal defect creation when left atrial decompression is indicated. This syndrome was the commonest cause of death from congenital heart disease in the first month of life in our recent experience (31 percent), based on a consecutive autopsy series of 174 neonates with congenital heart disease.The anatomic findings in 10 autopsy cases of interrupted aortic arch are summarized. A new understanding of the morphogenesis of these anomalies is presented, based on correlation of embryologic and pathologic data. The literature on interruptions of the aortic arch is reviewed, and surgical experience with these malformations is considered in detail.