Objective: Compared to heterosexual men, gay and bisexual men (GBM) are at an increased risk of adverse mental and sexual health outcomes. The psychological mediation framework (PMF; Hatzenbuehler, 2009) posits that minority stress is associated with changes in cognitive, affective, and social psychological processes, thereby leading to negative mental health outcomes among sexual minority individuals. This study examined whether these psychological processes account for the relationship between minority stress and poor mental health among GBM and extended the PMF to examine the effects on sexual health outcomes. Method: HIV-negative GBM (N = 465) completed a battery of self-report questionnaires assessing minority stress; cognitive, affective, and social processes; and mental and sexual health outcomes. Structural equation modeling was used to examine study hypotheses. Results: Findings partially supported the PMF by demonstrating that affective and social factors had a significant indirect effect in the relationship between minority stress and mental health outcomes; however, cognitive factors were nonsignificant. A significant indirect effect was found for cognitive factors in the relationship between minority stress and sexual health outcomes, whereas affective and social factors were nonsignificant. Conclusion: By uncovering the mediators underlying the relationship between minority stress and poor health outcomes, these findings have important clinical implications in the development of future interventions aimed at reducing adverse stigma-related health outcomes among GBM. The differential pattern of findings in the mental and sexual health models suggests that different psychological processes may need to be targeted in the treatment of mental health versus sexual health problems.