To compare the sexual behaviour and HIV risk reduction strategies of gay and bisexual men in Europe, a survey, disseminated via the gay press and gay associations, was conducted amongst gay and bisexual men in Austria, Switzerland, Germany, Denmark, France, Great Britain, Italy and the Netherlands during the autumn and winter of 1991. By end March of 1992, 12,347 completed questionnaires had been obtained. A preliminary analysis shows striking similarities in patterns of sexual behaviour of gay men in the 8 European countries but indicates that strategies of risk management concerning HIV and AIDS vary widely. While the majority of gay men have multiple partners, and intercourse is more common with stable partners than with causal partners. The proportion of men who, during the past 12 months, engaged in unprotected anal intercourse with a partner with different or unknown HIV-status ranged from 1/3 in East Germany to 1/6 in UK. However, reported incidence over the past 12 months of STDs, other than HIV infection, was similar in all countries (2%-3%). The reported HIV antibody prevalence varied from less than 7% in East Germany, Italy and the United Kingdom to 15% in Denmark and 17% in France. HIV risk reduction strategies appear to be most common in those countries where the gay community had been included in targeted prevention campaigns during the early phase of the AIDS epidemic. Considering the high proportion of gay men engaging in high risk activities it is imperative that prevention efforts are sustained and improved.