This presentation will discuss the numerous methodological and practical limitations of research and surveillance on male same-sex relations and HIV, including the diversity of men who have sex with men (MSM) (e.g., many have female partners, are married, engage in commercial sex, or use drugs), low representativeness of many study samples, problems with asking about sex with men when both “sex” and “men” are ambiguous terms (e.g., sex with transgender persons); and laws and state practices criminalizing homosexuality. Existing efforts of national HIV/AIDS programs have not adequately reached these groups with prevention and care at sufficient scale, and resources do not match the burden of disease. We will analyze how risk and vulnerability to infection are reinforced by societal attitudes, which, in most of the world, deny human rights and the right to health for MSM and transgender people. Finally we will discuss how a social inclusion perspective on HIV prevention and care implies the adoption of strategies to understand and confront social vulnerability. As part of a comprehensive response there is an urgent need to:  improve our understanding of the characteristics and HIV burden among sexually diverse populations; creatively confront legal, social and cultural factors enhancing sexual exclusion; ensure the provision of broad-based and effective HIV prevention; offer adequate care and treatment; and confront special challenges that characterize work with this population.