Summary: Gay men and other men who have sex with men (MSM) bear a disproportionately heavy burden of the HIV pandemic. In low- and middle-income countries, MSM are 19 times more likely to be infected with HIV than the general population. Despite elevated HIV prevalence rates and heightened vulnerability to factors that drive HIV transmission, MSM have been under-recognized, under-studied, under-funded, and under-served historically in the global response to HIV & AIDS. The Global HIV Prevention Working Group estimates that HIV prevention services reach only 9% of MSM worldwide. Such efforts designed to reach MSM are highly critical in addressing HIV in the broader population as well given the fluidity of social and sexual networks and in specific cases, other factors including presence of female partners, pressure to have children, and fear of public humiliation or blackmail. Additionally, the detrimental effects of stigma and discrimination on sexual health have been well documented in the global north, where HIV infection rates among MSM in large urban centers are unacceptably high and in some places steadily increasing. Furthermore, as of May 2009, criminal penalties for same-sex acts between consenting adults were executed in at least 80 countries,a driving the epidemic underground. There is therefore an urgent need to prioritize outreach to MSM with HIV-related services and information that effectively meet their needs in the contexts of global public health and human rights.