We present a case of a 10-month-old boy with BA who developed HCC and was treated with liver transplantation. A four-month-old boy was referred to our institution because of persistent jaundice, hepatomegaly, and coagulopathy. He had been treated for the diagnosis of neonatal hepatitis at an outside hospital. He was evaluated and was accepted as a liver transplant candidate, and was subsequently transplanted with a deceased donor liver allograft at the age of 10 months. His native liver showed established cirrhosis because of BA with one focus of moderately differentiated HCC, measuring 0.7 cm in a diameter with microscopic vascular invasion in pathological study. The postoperative course was uneventful, and he is well without recurrence four months after liver transplantation. The occurrence of HCC in a child under one yr old is extremely rare, and only three cases are reported so far including our case.