This essay explores the relationship between diversity and public health by addressing tensions related to classifications and recognition in the field of HIV and AIDS policy. The objective is to reflect on how classificatory and operative categories are articulated within the scope of programmatic responses towards the social production of differences and inequalities. To do so it draws from the theoretical framework of studies on vulnerability and recognition and from a methodology that includes a critical review of the literature on the category men who have sex with men (MSM) and ethnographic material, derived from the authors' research and a literature review related to social movements, and research and policies focused on lesbians, gays, bisexuals, transvestites and transsexuals (LGBT). It reviews how the MSM category was constructed in the field of HIV and AIDS prevention policies at an international level, situating political actors and tensions. It problematizes these tensions by analyzing processes of production of political subjects as well as changes in socio-state relations that involve LGBT. It emphasizes the importance of considering how differences and inequalities emerge in socio-political processes and of dedicating studies to improve policies, ensuring an effectively more respectful care.