The prevalences of antibodies to hepatitis C virus (anti-HCV), human immunodeficiency virus (anti-HIV), human T lymphotrophic virus (anti-HTLV) and of hepatitis B surface antigen (HbsAg) were determined in 168 subjects aged 12 years and over (108 Pygmies, 60 Bantus) living in south Cameroon. In 167 subjects, we found an estimated minimal anti-HCV prevalence of 13%. The prevalence was significantly higher in Bantus (31.7%) than in Pygmies (11.1%) and increased with age in both groups, albeit more rapidly in Bantus. The overall prevalence of HBsAg was 7.2% and correlated with neither sex nor ethnic group. No association was found between anti-HCV and HbsAg prevalence rates. No subject was confirmed to be positive for HTLV or HIV. These findings confirm the high prevalence of HCV infection in south Cameroon and indicate that even secluded population groups are affected.