Introduction In 2011, Malawi implemented “Option B+,” a test‐and‐treat strategy for the prevention of maternal to child transmission of HIV (PMTCT); however limited data on viral load (VL) suppression exist. We describe VL suppression in HIV‐infected women at four to twenty‐six weeks postpartum, factors associated with VL suppression and the impact of VL suppression levels on MTCT. Methods HIV‐positive mothers at four to twenty‐six weeks postpartum were enrolled in a nested cross‐sectional study within the “National Evaluation of Malawi's PMTCT Programme” cohort study between October 2014 and May 2016. HIV‐exposed infants received HIV‐1 DNA testing and venous samples determined maternal VL, classified as unsuppressed (>1000 copies/mL), low‐detectable (40 to 1000 copies/mL) or undetectable (