Characteristics of bisexually-active men were compared with those of their homosexually-active counterparts in a study of HIV-seropositive men who have sex with men (MSM). Men who had had sex with women in the prior year were younger and more likely to be African American than those reporting sex only with men. They reported higher levels of internalised homophobia and less participation in the gay community. They tended to be recruited through friend referral rather than public sex environments or AIDS service organisations. However, they did not seek sex partners from different venues than other participants. Implications for HIV transmission risk-reduction interventions for this population are discussed.