The prevalences of hepatitis B virus (HBV) markers on an isolated island in Shimane Prefecture were examined. Serum samples were collected from 294 (62.8 per cent) of 468 individuals aged 20-64 years old living in three villages on the island. The prevalence of hepatitis B surface antigen (HBsAg) was 6.5 per cent and the highest rate was found in the 40-49 years age group (12.7 per cent). The comparison of HBsAg carriers and controls demonstrated differences according to "Blood transfusion" experience and "Previous liver disease".