80 patients with pulmonary atresia and subaortic ventricular septal defect had complete angiography with right ventricular, aortic and selective arterial angiograms to delineate the anatomy of the central pulmonary arteries and the systemic supply to the lungs, as correct management of the patient depends on this. In 67 (85 p. 100) there were 1-5 large congenital systemic collateral arteries mainly arising at or below the aortic isthmus. This group, referred to as "complex pulmonary atresia" with right aortic arch in 30, had variable central pulmonary artery development, either completely absent in 17, hypoplastic in 33 (49 p. 100) appearing as a "seagull" (une mouette) in the mediastinum on late films or large well developed vessels in 17. Patients with hypoplastic central arteries require special management. We now perform a two stage procedure, initially placing a conduit containing a homograft aortic valve between the right ventricle and small central pulmonary arteries in order to develop them and leaving the ventricular septal defect open. Initial results in 6 patients treated this way are encouraging and it is proposed to close the defect later after enlargment of the pulmonary arteries has occurred.