In the neonate with cholestasis, clinical features and standard tests of liver function frequently cannot distinguish between diseases of the hepatocyte and those of the biliary tree. Therefore, a multidisciplinary approach to diagnosis is required. A priority in investigation is the identification of patients requiring surgery. A correct diagnosis regarding the need for surgery can be made in the majority of cases after synthesis of information obtained from abdominal sonography, hepatobiliary scintigraphy, and liver biopsy. Intraoperative cholangiography is performed routinely to precisely delineate the anatomy of the intrahepatic and extrahepatic bile ducts.