A total of 1,442 schoolchildren in the Matsumoto City area were investigated for the prevalence of hepatitis virus-related serum markers, including antibody to hepatitis C virus (anti-HCV) and an abnormal serum transaminase level. Despite the large number of children tested, none was positive for anti-HCV antibodies or had been diagnosed as having viral hepatitis. The prevalence of anti-HCV antibodies in children and adult blood donors in the same area increased significantly with age from 0% in the 6–15-year-old group to 1.14% in the 50–65-year-old group (P < 0.001). Our results indicate that even if only the enzyme-linked immunosorbent assay results confirmed by the recombinant immunoblot assay are considered positive, the prevalence in children is significantly lower than that in blood donors (P < 0.05). Six children were healthy carriers of hepatitis B virus (HBV); all had been born to carrier mothers. These results indicate that apparently healthy schoolchildren in Japan have a low exposure to HCV infection.