This paper describes the sexual risk practices of 322 HIV-positive gay and bisexual men who reported having unprotected anal, oral or vaginal sex with an HIV-negative or unknown status partner(s) during the previous four months. Descriptive data on type of sex, partner types and number of partners are presented. Determinants of unprotected anal and oral intercourse were examined using a social cognitive framework. More unprotected anal sex was associated with having a steady versus a casual partner, not being on triple drug therapy, increased use of drugs and alcohol, and lower outcome expectancies for condom use and negotiation of safer sex practices. Unprotected oral sex was associated with partner type; men with casual partners had less unprotected oral sex as compared to men with steady partners. Findings are discussed in relation to the development of sexual risk reduction interventions for HIV-positive individuals.