Male homosexuals attending venereal clinics seem to be a group frequently exposed to hepatitis B virus. In the present study male homosexuals attending a club for homosexuals were also investigated. The latter group was found to have a lower risk of exposure to hepatitis B virus than homosexuals attending venereal clinics as measured by HBsAg or anti-HBs in serum (27% versus 46%). Both groups of homosexuals, however, had a higher frequency of hepatitis B markers in serum than heterosexual males attending venereal clinics (11%). As far as the risk for hepatitis A virus exposure is concerned, the prevalence of anti-HAV antibodies was similar in both groups of homosexuals as well as in the heterosexual controls (15–19%). However, these prevalences of anti-HAV are also higher than among age-matched Swedish blood donors (3–9%).