HIV/AIDS is a serious health problem among prisoners and constitutes a big challenge for prison administration services, public health services and governments. <b><span style="font-family:Verdana;">Aims</span></b><span style="font-family:Verdana;"><strong>:</strong> Determine the prevalence of HIV infection among prisoners and describe associated factors. </span><b><span style="font-family:Verdana;">Population and Methods: </span></b><span style="font-family:Verdana;">This was a descriptive and analytical cross-sectional study conducted from December 2015 to October 2016. A sample of 600 prisoners was randomly interviewed nationwide. They were selected directly from the sample frame from across the country and proportionally from all sites. Pre-established questionnaires providing information on the sociodemographic and biological characteristics of prisoners were used for the collection of data. Data entry and analysis were </span><span style="font-family:Verdana;">performed using EXCEL and SPSS 18 software. </span><b><span style="font-family:Verdana;">Results: </span></b><span style="font-family:Verdana;">The survey was</span><span style="font-family:Verdana;"> based on a randomised sample of 600 prisoners, 593 of whom accepted blood extraction for the HIV testing. The series was mainly composed of males (89%). The median age was 33 years (18 -</span><span style="font-family:'';line-height:1.5;"> </span><span style="font-family:'';line-height:1.5;"><span style="font-family:Verdana;">69). The level of education among respondents was 60%. Regarding marital status, the proportion of married prisoners was 51.8%. Almost three-quarters (71.5%) were at their first imprisonment and 51.8% were on preventive detention. The reasons for imprisonment varied and were dominated by drug use (35.3%), while only 4.6% confessed that they continued using drugs while in prison. 97.8% of prisoners have had a sexual experience. Their median age was 19 years at their first sexual intercourse. 20.5% reported using a condom during thei