The prison is characterized by a high risk of HIV transmission. For an effective control, it is necessary to know the attitudes of inmates on the screening and the prevalence of infection in this marginalized population. It was for us to describe the sociodemographic characteristics of the respondents, to know their attitudes towards the HIV test, and to determine the seroprevalence of HIV. We led to the MACO, from March 10 to 24, 2014, a descriptive transvers study. Were included, the inmates in the prison during the study period, randomly drawn, with at least one month in detention, and who agreed in a free and lit way, to participate in the study. For the screening of the HIV infection, the test was systematically proposed to every participant who marked his agreement by signing a sheet of consent. During the study period, 419 male majority-owned (95%), young (mean age 31 years) were surveyed. Over 54% of respondents had never done the HIV test. Fear of discovering infected (62%) was the main reason for non-completion of the test. On 280 inmates who agreed to testing, the serology returned positive in the HIV1 to five investigated, is a HIV prevalence in 1.8 %. The HIV prevalence in MACO remains very high compared to the general population of Burkina Faso. Urgent action is needed to raise awareness.