Biliary atresia (BA) is an obliterative cholangiopathy affecting the extra- and intrahepatic bile ducts which presents in the first few weeks after birth with jaundice, pale stools, and dark urine. Biliary atresia is the most common cause of liver transplantation in children. Infants with BA will present with conjugated jaundice that persists beyond 14 days of age, pale stools, and dark urine. Liver fibrosis and cirrhosis occur earlier in BA relative to other neonatal cholestatic liver diseases such as Alagille syndrome. The etiology of BA is essentially unknown, although two broad mechanisms have been suggested including a congenital and a perinatal form. Ultrasound examination is an important part of the diagnostic work-up as this can exclude other possible surgical diagnoses such as choledochal malformation. An atrophic or nonemptying gallbladder may be suggestive of BA. The preferred treatment of infants with BA is radical surgical excision of the extrahepatic bile ducts and Roux loop reconstruction or Kasai portoenterostomy.