To understand sexual decision-making processes among people living with HIV, we compared safer sex self-efficacy, condom attitudes, sexual beliefs, and rates of unprotected anal or vaginal intercourse with at-risk partners (UAVI-AR) in the past 3 months among 476 people living with HIV: 185 men who have sex with men (MSM), 130 heterosexual men, and 161 heterosexual women. Participants were enrolled in SafeTalk, a randomized, controlled trial of a safer sex intervention. We found 15% of MSM, 9% of heterosexual men, and 12% of heterosexual women engaged in UAVI-AR. Groups did not differ in self-efficacy or sexual attitudes/beliefs. However, the associations between these variables and UAVI-AR varied within groups: greater self-efficacy predicted less UAVI-AR for MSM and women, whereas more positive condom attitudes--but not self-efficacy--predicted less UAVI-AR for heterosexual men. These results suggest HIV prevention programs should tailor materials to different subgroups.