Although chronic infection with hepatitis B virus (HBV) is one of the major risk factors for liver cancer, the level of knowledge about liver cancer risk factors and HBV transmission, as well as vaccination have not been assessed in this population. We interviewed Hmong youth living in Fresno, California about liver cancer risk factors. General knowledge of HBV was common, but knowledge of specific modes of transmission was low. For example, only 49% knew that HBV was transmitted by sexual intercourse. We also observed very low prevalence of HBV vaccination (12%), although a majority reported knowing that shots can prevent disease (68%). Liver cancer prevention and control methods targeted to Hmong youth are needed.