Background: Low birth weight is an important risk factor for infant morbidity and mortality, especially in Sub-Saharan Africa where HIV prevalence is still high. This review focuses on the birth weight outcome of babies whose mothers are infected with HIV and on ART at University of Maiduguri Teaching Hospital (UMTH), Nigeria. Methods: A total of 90 mother-baby pairs were studied. Babies birth weights were measured using the bassinet weighing scale and data of HIV mothers that are on ART as part of prevention of mother to child transmission of HIV (PMTCT) at UMTH were obtained from their ANC hospital record. Results: There were 47 (52.2%) males and 43 (47.8%) females. Most babies 73 (81.1%) had acceptable birth weights. Of the 17 (100 %) babies with LBW, 10 (58.8%) were HIV exposed babies. Association between HIV exposed and non HIV exposed (controls) with birth weight outcome of these babies were not significant (p = 0.419). Conclusion: Majority of babies with LBW were HIV exposed whose mothers are on ART for PMTCT. Effective ART for PMTCT in pregnant mothers during ANC may have made the LBW in our babies of no significance. We therefore recommend ART to HIV pregnant women.