Background : Informal health care providers are key actors for health care provision in developing countries for poor populations. Thus, in Cameroon, in 2017, there were more than 3,000 Informal Health facilities. In a context of elimination of mother-to-child transmission of HIV, we describe the offer of Prevention of Mother to Child Transmission of HIV (PMTCT) in informal health centers. Methods : This two-phase cross-sectional study was carried out in two cities in Cameroon notably Douala and Ebolowa. The first step was conducted from March 2019 to July 2019 in 110 informal health centers and the second from August 2019 to January 2020 with 183 Health Providers in these informal health centers. Standardized questionnaires were administered. Data collected were entered in kobo Collect software. Descriptive statistics and logistic regression at a level of significance of 5% were used. Results : Of the 110 informal health centers, 109 integrated HIV testing into the antenatal check-up package. Among them, 43% (47/109) reported giving antiretroviral treatment to HIV infected pregnant women, while the remaining referred them to formal HIV care centers. Regarding delivery services, 52% (53/101) of those who offered them referred HIV exposed newborn for further PMTCT care. Knowledge of PMTCT was insufficient among 51% (94/183) of health providers and 90% (165/183) had insufficient PMTCT practices.  Health providers with no PMTCT experience were more likely to have insufficient knowledge of PMTCT (aOR= 32.04, 95%CI: 6.29 to 163.10, p<0.001) whereas, those without any formal PMTCT training were more at risk of having insufficient knowledge (aOR= 3.02, 95%CI: 1.06 to 8.64, p=0.03) and insufficient practices (OR= 4.35, 95%CI: 1.44 to 13.09, p=0.009) towards PMTCT. Conclusion : Given their proximity to the populations and the PMTCT activities they conduct most often; particular attention should be paid to PMTCT in informal health centers.