Conjugated hyperbilirubinaemia in an infant indicates neonatal liver disease. This neonatal hepatitis syndrome has numerous possible causes, classified as infective, anatomic/structural, metabolic, genetic, neoplastic, vascular, toxic, immune and idiopathic. Any infant who is jaundiced at 2-4 weeks old needs to have the serum conjugated bilirubin measured, even if he/she looks otherwise well. If conjugated hyperbilirubinaemia is present, a methodical and comprehensive diagnostic investigation should be performed. Early diagnosis is critical for the best outcome. In particular, palliative surgery for extrahepatic biliary atresia has the best chance of success if performed before the infant is 8 weeks old. Definitive treatments available for many causes of neonatal hepatitis syndrome should be started as soon as possible. Alternatively, liver transplantation may be life saving. Supportive care, especially with attention to nutritional needs, is important for all infants with neonatal hepatitis syndrome.