BACKGROUND/AIMS: Parenteral exposure, such as transfusion, drug abuse, needle stick injury, tatooing, hemodialysis and transplantation, is well documented as the major route of transmission. But about half of hepatitis C virus(HCV) carriers have no previous history of parenteral infection. Therefore, other possible routes of the spread should be evaluated. The possibility of intrafomilial transmission of HCV was considered to be low as compared to that of hepatitis B virus(HBV), but recent publications from Japan and Europe elicit the interest in intrafamilial transrmission, especially in spousal transmission. The aim of this study is to investigate the possibility of spousal transmission of HCV. METHODS: We analyzed clinical features, serum transaminase and anti-HCV in 56 spouses who got married to anti-HCV positive patients. The mean age in index cases was 44.7 years, 45.6 in male and 43.2 in female and that of spouses was 42.4 yenrs, 45.7 in male and 40.7 in female. The mean duration of marriage was 20,0 years, distributed from 1 to 50. Index cases included 8 asymptomatic carriers, 44 chronic hepatitis, 3 liver cirrhosis and 1 hepatoma. Four of those had previous history of blood transfusion. RESULTS: Among 56 spouses, anti-HCV was detected in 9 cases representing 16.1%. Four of those were clinically asymptomatic carriers and remaining 5 had chronic hepatitis. The mean age in index cases of anti-HCV positive spouses was 56 years old and was older than that of anti-HCV negative spouses 42.6(P<0.01). The mean duration of marriage in index cases of anti-HCV positive spouses was 30,9 years and was longer than that of anti-HCV negative spouses 18.0(P<0.05). CONCLUSIONS: This study revealed higher prevalence of anti-HCV in spouses who got married to anti-HCV positive carriers compared to that of general population. As the duration of marriage was getting longer, the frequency of anti-HCV in spouses increased(P<0.01). These results suggest that the spouses of anti-HCV positive carriers could be a high risk group for HCV transmission.