Male hypogonadism is poorly defined in people living with HIV. Using a reliable free-testosterone assay, we examined the prevalence and risk factors of male hypogonadism among people living with HIV on effective antiretroviral therapy. Male hypogonadism was found in 12.4% of patients, twice the rate reported in the general population of the same age. Two risk thresholds, namely 5 years of antiretroviral therapy and 19% total body fat, may help to identify patients at risk.