To effectively target HIV prevention activities, community outreach workers need to know how to locate persons at greatest risk for acquiring or transmitting HIV. This study compared the behavioral characteristics of HIV-positive men who have sex with men recruited from different sources: AIDS service organizations, mainstream gay environments, public/private sex environments, and friend referrals. Men recruited from sex environments exhibited the riskiest behavior: more male partners, more likely to have casual sex, more likely to have had unprotected insertive sex with men of HIV-negative or unknown status, less likely to have disclosed serostatus to primary partners, less comfortable discussing serostatus with others, and less feeling of personal responsibility for disclosure. A distinctive group of men, the referral group, did not identify with the gay community and reported sex with men and women. Future efforts should continue to assess the types of people that are recruited from different sources so that program and research efforts can be appropriately targeted.