Hypogonadism is a common complication among HIV infected patients. The prevalence of hypogonadism is 30 to 50% in HIV infected men with wasting syndrome and 20 to 25% in those without wasting syndrome. HIV infection affects the entire hypothalamus-pituitary-gonadal axis via both direct and indirect effects, which are defined in four categories, 1) direct effect of HIV particles, 2) opportunistic infections, 3) HIV-related malignancy and its treatment, and 4) medications that are used for HIV infection or its opportunistic infection. The association between HIV infection, hypogonadism, and cardiovascular diseases has yet to be determined; however, there are data that HIV infection and its treatment, particularly protease inhibitors, worsened the metabolic profiles, which were surrogate markers of cardiovascular diseases. Considerably more attention should be paid to the diagnosis of hypogonadism in this group particularly because HIV infection increases both sex hormone-binding globulin and total testosterone level. Testosterone replacement shows benefits on mood, body composition, and seems to benefit the metabolic profile in HIV infected men with low body mass index.