BACKGROUND/AIMS: Hepatitis C virus (HCV) infection is known to be prevalent in leprous patients Hepatitis G virus (HGV) is transmitted parenterally as HCV. This study was performed to assess the prevalence of HGV infection in leprous patients and non-leprous family members of leprous patients METHODS: This study included 96 leprous patients and 47 non-leprous family members of leprous patients. HCV-antibody was tested by the 3rd generation enzyme linked immunosorbent assay (ELISA). Anti-HCV positive sera were confirmed by the 2nd generation recombinant immunoblot assay (RIBA) and reverse transcription-polymerase chain reaction (RT-PCR) from 5 ?-UTR. HGV-RNA was detected by RT-PCR from E1 region. RESULTS: The prevalence of HCV infection in the leprous patients (55.2%) and the non-leprous family members (8.5%) was higher than that of genera population of Korea. The prevalence of HGV infection in the leprous patients and their non-leprous family members was 10.4% and 6.4% (95% confidence interval, 5.1-18.3%), respectively. These values were higher than that of general population (1.4%). The higher prevalence of the HGV infection in the leprous patients was not related with leprosy nor HCV infection. CONCLUSIONS: Leprous patients are exposed to high risk of HGV infection as well as HCV infection.