nfantile jaundice (conjugated hyperbilirubinemia) is the common presentation of biliary atresia, idiopathic neonatal hepatits infectious hepatitis and metabolic disorders. A timely diagnosis is essential to the management of these children. The investigation of hepatobiliary disease in this age group frequently includes a liver biopsy which, if optimally handled, provides tissue for a focused investigation. This is dependent upon consideration of the history prior to biopsy. The histologic picture, together with special investigations, provides a diagnosis in many instances. In those disorders with histologic change suggestive of a diagnosis ancillary laboratory studies may include special enzyme or compound analyses, as well as molecular studies. This overview provides an approach to the pathologist who may infrequently encounter this problem, and includes biopsy processing, pathology and special investigations.