A newborn infant, who was low-birth weight(1,780gm), showed severe degree of jaundice on second day of life and skin color became dark greenish-yellow and moderate hepatosplenomegaly was noted on physical examination. Results of liver function test & radioimmuniassay for hepatitis B antigen of both infant and mother suggested that neonatal hepatitis B seemed to occure transplacentally during pregnancy from infected mother. Pancytopenia was followed, but we could not confirm aplastic anemia due to lack of bone marrow specimen. As mentioned above, we experienced a case of vertically transmitted neonatal hepatitis B with pancytopenia. We present a brief review of related literatures.