ABSTRACT: BACKGROUND:HBV, HCV, HDV and HIV are blood borne and can be transmitted from mother-to-child. Reports of HBV infection rates show up to 11.9% in Cameroon while for HCV, the rate is less than 2%. More so, as pregnant women get enrolled in the HIV PMTCT Programme and stay in the care continuum, selection of HIV-1 drug resistant strains is evident. We sought to determine the seroprevalence of HBV, HCV, HDV and HIV among pregnant women, assess their knowledge, attitudes and practices on transmission and prevention of HBV infection, and determine HIV drug resistance profile of breastfeeding women. METHODS:A serosurvey of HBV, HCV, HDV and HIV was carried out among 1005 pregnant women in Yaounde, Cameroon. In 40 HIV-infected breastfeeding women enrolled in the PMTCT Programme, HIV-1 genotypes and HIV-1 resistance to NRTIs, NNRTIs and PIs, were determined by phylogeny and the Stanford University HIV Drug Resistance interpretation tool, respectively. RESULTS:Among the pregnant women, the rates of HIV-1, HBV, HCV and HDV infections were 8.5, 6.4, 0.8 and 4.0%, respectively. About 5.9% of the women knew their HBV status before pregnancy unlike 63.7% who knew their HIV status. Although 83.3% reported that vaccination against HBV infection is a method of prevention, and 47.1% knew that HBV could be transmitted from mother-to-child, only 2.5% had received the Hepatitis B vaccine. Of the 40 women on antiretroviral therapy (ART), 9 had at least one major resistance-associated mutation (RAM, 22.5%) to NRTI, NNRTI or PI. Of these M184?V (12.5%), K70R (10.0%), K103?N (12.5%), Y181C (10.0%), M46?L (2.5%) and L90?M (2.5%) were most frequently identified, suggesting resistance to lamivudine, nevirapine, efavirenz and zidovudine. Eighty four percent were infected with HIV-1 recombinant strains with CRF02_AG predominating (50%). CONCLUSIONS:The rates of HBV and HIV-1 infections point to the need for early diagnosis of these viruses during pregnancy and referral to care services in order to minimize the risk of MTCT. Furthermore, our results would be useful for evaluating the HIV PMTCT Programme and Treatment Guidelines for Cameroon.