Extrahepatic biliary atresia is a disease of unknown cause, leading to profound cholestasis and progressive biliary cirrhosis. This paper discusses the diagnosis and management of this condition. It is stressed that bile flow can be established in 80-90% of infants referred to surgery within 60 days after birth. Liver transplantation is essential for infants who are referred late (120 days of age or later); those whose initial portoenterostomy was not successful, and those who develop end-stage liver disease in spite of bile drain-age.