RATIONALE:Experiences of weightism are associated with reduced psychological quality of life among heterosexual men and women. However, despite noted vulnerability to body image pressures, weightism has not been quantitatively examined among sexual minority men. We tested two hypotheses: first, that Body Mass Index (BMI) and weightism would evidence a curvilinear relationship, such that underweight and overweight men would report experiencing more weightism than men in the "normal" weight range; and second, that a negative association between BMI and quality of life would be explained by experiences of weightism and body dissatisfaction. METHOD:Sexual minority men living in Australia and New Zealand (N = 2733) completed an online survey and provided data on their height, weight, experiences of weightism, body dissatisfaction, and psychological quality of life. RESULTS:Participants' BMIs ranged from 14.15 to 68.12 with 3.0% classified as underweight, 50.5% as "normal" weight, 28.0% as overweight, and 17.4% as obese. Weightism was experienced by 38.9% of participants. As predicted, weightism evidenced a curvilinear relationship with BMI, such that underweight and overweight participants reported experiencing more weightism relative to "normal" weight participants. Yet, this curvilinear relationship evidenced a dominant linear component: Overall, weightism markedly increased as BMI increased, and obese participants reported experiencing the most weightism. In addition, we found evidence supporting our hypothesis that men with higher BMIs would report experiencing more weightism and higher body dissatisfaction, and through these variables, reduced quality of life. Adjusted for body dissatisfaction and weightism, the formerly negative association of BMI with psychological quality of life became (weakly) positive. CONCLUSIONS:Weightism is a salient phenomenon experienced by sexual minority men in smaller and larger bodies with potential direct and indirect adverse effects on psychological quality of life. Whilst BMI and weightism evidenced a curvilinear relationship, the burden of weightism is disproportionately borne by sexual minority men with higher BMIs.