Biliary atresia (BA) is the end result of a destructive, inflammatory process that affects intra- and extrahepatic bile ducts, leading to fibrosis and obliteration of the biliary tract with the development of biliary cirrhosis. It is the commonest cause of chronic cholestasis in infants and children, and therefore is the most frequent indication for liver transplantation in this age group. The disease occurs worldwide, affecting an estimated 1 in 8,000 to 12,000 live births. At present, there is no specific therapy for BA; however, sequential surgical therapy begins with creation of a hepatoportoenterostomy (HPE); in those with end-stage liver disease, liver transplantation is indicated. Since most candidates are young children of small size, there is a shortage of size-matched donors for liver transplantation. At present, an increased awareness to ensure early diagnosis and development of methods to prevent progressive fibrosis are needed. These considerations are dependent on detailed studies of the pathogenesis of BA. Recent studies have focused on normal and altered bile duct morphogenesis and the role of various factors (infectious or toxic agents and metabolic insults) in isolation or in combination with a genetic or immunologic susceptibility in the etiology of BA.