A new syndrome is described of which the salient features are (1) congenital hypoplasia and stenoses of the pulmonary arteries, sometimes with associated cardiovascular malformations; (2) neonatal liver disease, commonly with obstructive jaundice and resembling biliary atresia or neonatal hepatitis, but sometimes apparent only as mild persistent hepatic dysfunction; and (3) various minor congenital anomalies, including an odd facies. There is a familial tendency suggesting autosomal dominant inheritance, with variable penetrance.