HIV infection remains a major public health problem in sub-Saharan Africa. In Chad, HIV is a widespread and evolving type, and voluntary testing is a necessary and responsible act. The objective of this study is to present the frequencies of clients screened and pregnant women for prevention of mother-to-child transmission (PMTCT). The study is cross-sectional and retrospective, based on the results of voluntary screening in N'djamena and provinces during the period from April to June 2016. In total, 91,767 clients were screened, of whom 18,688 (20.30%) were men, 21,853 (23.74%) were women and 51256 (56.59%) were pregnant women. 4,647 tests were positive and confirmed to be 5.06%. Screening is one way of preventing HIV / AIDS. It allows for early identification of HIV status in order to change risk behaviors, facilitate access to antiretroviral therapy, and reduce mother-to-child transmission