Background: Hepatitis C virus has an important etiologic role in hepato-cellular carcinoma in HBsAg negative patients in Korea. Superinfection of hepatitis C virus is not infrequent and may modify the natural course of chronic HBV infection.This study was aimed to investigate the prevalence of anti-HCV among the general population in Mokpo, Korea. Methods: We evaluated the anti-HCV seropositivity from 1,299 persons who visited the Health Clinic Center, Anti-HCV was detected by enzyme immunoassay method. Results: Twenty three (1.77%) were positive for anti-HCV, and twenty (1.54%) persons were male. Male to female ratio was 6.7:1. The prevalence of anti-HCV among male subjects (1.54%) was higher than that of female subjects (0.237o). Among twenty three persons who had anti-HCV positivity, 14(61%) had normal values of serum AST and ALT and 8 (35%) had two fold elevated values of serum AST and ALT. Twenty three persons who had anti-HCV positivity were negative for HBsAg. But 14 (617c) persons were positive for IgG anti-HBc. Conclusions: Anti-HCV prevalence increased with age through the fifth decade of life. The prevalence of antibody to HCV in Mokpo, Korea was 1.77%. And it was predominant in ma]e. (Korean J Gastroenterol 1996;28:677 - 682)