Background. In hepatocellular carcinoma (HCC), a high prevalence of hepatitis C virus antibody (anti‐HCV) has been reported, indicating that it may be an important etiologic factor in the pathogenesis of HCC. In this study, the authors investigated the prevalence of anti‐HCV in HCC patients, as well as the same prevalence in patients with cholangiocarcinoma (CC) and combined hepatocellular–cholangiocarcinoma (combined HCC‐CC), to study the clinicopathologic features of anti‐HCV–positive cases. Methods. The authors examined 141 patients with primary liver cancer who were pathologically diagnosed as having HCC (121 cases), CC (13 cases), or combined HCC‐CC (7 cases). Hepatitis B surface antigen (HBsAg) and anti‐HCV were measured in these patients. Results. Of 121 HCC cases, 85 (70.3%) were found to be anti‐HCV positive, 16 (13.2%) were HBsAg positive, and 5 (4.1%) were both anti‐HCV and HBsAg positive. In 13 cases with CC and in 7 with combined HCC‐CC examined, 4 (30.8%) and 5 (71.4%), respectively, were anti‐HCV positive. Conclusions. The anti‐HCV–positive rate was high in combined HCC‐CC as well as in HCC. These three types of primary liver cancer, which were anti‐HCV positive, shared two common features: male dominance and high incidences of complication with liver cirrhosis.