Using representative samples from populations of 19 sub-Sahara African countries, this paper investigates the effects of different levels of HIV/AIDS knowledge on sexual behavior of males with country specific effects and controls for socioeconomic characteristics and location of residence. The main findings are that HIV/AIDS knowledge increases the likelihood of using condoms with and without commercial sex workers, has no significant effect on the likelihood of paying for sex, and increases both the likelihood of having pre and extra marital sex. These results indicate that increased HIV knowledge on average does not lead to safer sexual behavior of males in sub-Saharan Africa at the macro level.