An adult-type of primary hepatocellular carcinoma associated with HBV infection occurring in a 14-year-old boy is reported. Serological examination of his mother revealed the prese- nce of HBc-Ab suggesting familial transmission of HBV infection to the patient in his early life. There was no history of chronic liver disease and no clinical evidence of liver cirrhosis. Histological examination taken from needle biopsy revealed an adult-type HCC without histological features compatibie with hepatoblastoma. The present case with HBs-Ag-positive HCC in childhood may imply the significant relationship between HBV and HCC not only in adult but also in chiidhood.