We report on the results of a respondent-driven sampling survey among men who have sex with men (MSM) in Kampala, Uganda, where same-sex behavior is criminalized and highly stigmatized. We enrolled 608 MSM aged 18 + years and residing in greater Kampala from June 2012-November 2013. Anonymous data were collected through audio-computer assisted self-interviews; blood was tested for HIV-1 antibodies, CD4 + T cell counts, and viral load. Estimated HIV prevalence was 12.2 % (95 % confidence interval [CI] 8.0-16.1), increasing with age. One in five (19.6 %) stated knowing their HIV-positive status and a similar proportion of HIV-infected MSM were virally suppressed (19.3 %; 95 % CI 3.3-33.1). HIV-related risk behaviors included unprotected anal sex (35.8 % at last sex act), selling sex (38.5 %), having multiple steady (54.3 %) or casual (63.6 %) partners, and ever injecting drugs (31.6 %). Forty percent experienced homophobic abuse; 44.5 % ever experienced suicide ideation. HIV prevalence among MSM remains high whereas knowledge of seropositive status and suppression of viral load remains low. MSM report a wide range of high risk behaviors, frequent homophobic abuse, poor mental health, as well as low levels of testing and treatment. Better access to tailored prevention and treatment services to improve population-level viral load suppression are warranted.