African women of childbearing age are particularly vulnerable to HIV infection, and this has led to an increase in the number of pediatric HIV infections reported due to the risk of mother-to-child transmission (MTCT) of HIV during pregnancy, delivery and breastfeeding. Various approaches to preventing MTCT have been, or are being, evaluated in developing countries, especially in Africa. New data from these trials are becoming available and have implications for population-based intervention programs that require urgent consideration. We performed a critical review of 18 randomized trials and other relevant studies from developing and industrialized countries, to assess public health perspectives and to identify new research issues. Most African results relate to trials of antiretroviral drugs (ARVs) given to mothers during the last month of pregnancy, and for up to one week after delivery, and to the neonate during the first week of life, or simpler and shorter regimens. They indicate that zidovudine treatment, with or without lamivudine, and nevirapine treatment given alone, reduce transmission during the first six months of life by 30 % to 50%. Preliminary results suggest that zidovudine treatment is effective in the long term. One randomized study showed that the replacement of breast feeding with breast milk substitutes was effective at reducing the overall risk of MTCT. Antiseptic disinfection and micronutrient supplementation have been shown to reduce maternal and infant mortality and morbidity, but not the MTCT of HIV. Voluntary, confidential HIV counseling and testing for pregnant women, a short course of peripartum ARVs and alternatives to breast feeding such as early weaning and breast milk substitutes from birth, are currently the best means of reducing the MTCT of HIV in Africa. Pilot programs based on these findings are currently being implemented in several African countries. Prevention of the MTCT of HIV should also be considered as part of the wider management of maternal and infant health during prenatal, delivery and postnatal care. Several complementary issues require further investigation. Some results, such as the long-term efficacy of a short course of ARVs once the mother has finished breast feeding, and the long-term safety of these treatments, require confirmation. Further studies are required into the prevention of postnatal transmission, particularly in light of the unknown consequences of different feeding options and the possibility of post-perinatal prophylaxis with ARVs. The reduction of MTCT of HIV in Africa is a true challenge in efforts to control the HIV pandemic, but recent progress in the identification of effective treatments provides some hope. Large-scale implementation of these new treatments is required, and should provide practical information and perhaps identify more potent, and possibly cheaper, strategies.