During a 12 year period from 1978 to 1989, 35 infants under 4 weeks of age underwent palliative surgery for complex congenital cyanotic heart disease with a short (1-1.5 cm) PTFE graft between the ascending aorta and the right pulmonary artery (modified Waterston shunt). Twenty-three infants had pulmonary atresia and 14 had severe pulmonary stenosis. Underlying cardiac lesions were tetralogy of Fallot (n = 11), single ventricle (n = 7), transposition complexes (n = 6), and intact ventricular septum and hypoplastic right heart syndrome (n = 13). There were 4 early deaths (10.7%) in the entire series, 2 of which were shunt related. Three of the 4 occurred during our initial experience with this shunt in 1978 and 1979. They led to the modified Waterston shunt being abandoned for 3 years in favor of other shunt procedures. Since 1983 one early death occurred in 28 infants (3.5% mortality) with no death in the latest 26 patients. All patients were followed up between 6 and 108 months. There were 4 late deaths, one of which was shunt related. We observed a significant difference in the shunt patency rate between 4 and 5 mm grafts: palliation was adequate after 2 years in 52% of the patients when a 4 mm graft was used and in 89% of the 5 mm graft group (p less than 0.005). Reshunting was necessary in 7 infants between 5 and 60 months after primary surgery. Recatheterization was performed in 17 infants for suspected shunt failure (n = 6) or diagnostic reasons (n = 11).(ABSTRACT TRUNCATED AT 250 WORDS)