To date very little literature exists examining theoretically-based models applied to day-to-day positive and negative affective well-being among lesbian, gay, and bisexual (LGB) persons living with HIV/AIDS (PLWHA). Grounded in the perspective of Meyer, I. H. (2003). Prejudice, social stress, and mental health in lesbian, gay, and bisexual populations: Conceptual issues and research evidence. Psychological Bulletin, 129, 674-697. Minority Stress Model, the present study examined HIV- and sexual orientation-related factors influencing affective well-being (i.e., positive affect, negative affect, life satisfaction, and stress). Participants were 154 HIV-positive LGB adults from an urban area in the southwestern United States. Data were drawn from an archival database (i.e., Project Legacy). The study methodology featured a cross-sectional self-report survey of minority stress, victimization, coping, and emotional well-being, among other subjects. Primary regression results were: (1) males reported less general stress than females; (2) higher internalized HIV-related stigma was associated with elevated negative affect; (3) higher internalized homophobia was associated with elevations in negative affect and general stress; (4) higher coping self-efficacy was associated with lesser negative affect, lesser general stress, greater positive affect, and greater satisfaction with life; (5) a significant interaction between HIV-related victimization and coping self-efficacy showed that coping self-efficacy was positively associated with positive affect only (only for non-victims). Contrary to expectations, coping self-efficacy demonstrated the largest main effects on affective well-being. Results are discussed with regard to potential need for theoretical refinement of Minority Stress Model applied to PLWHA and affective well-being outcomes. Recommendations are offered for future research.