Mother-to-child transmission (MTCT) is a major route of HIV infection among children globally and if not treated these children are most likely to die before they reach ten years. In actual fact >90% of HIV infection among children is due to vertical transmission of HIV from the mother to her child. MTCT is preventable and could be eliminated, if infected expectant mothers could be identified and treated early. Currently it is possible to reduce the MTCT risk to <2%. Furthermore, if antiretroviral therapy is used, combined with caesarean section delivery and avoidance of breastfeeding, the chances of passing on HIV infection to babies can be reduced to one-fourth of the expected transmission rate. It is important that HIV-infected pregnant women know their status in order to protect their own health and reduce the risk for transmitting HIV to their infants. Diagnosis allows a woman to receive appropriate treatment to improve the chances that her infant will be born free of infection. In addition, it may prevent transmission of HIV to her sexual partner if not yet infected. Universal testing of all pregnant women is highly recommended and for developing countries at the heart of the AIDS epidemic, it is an essential step in preventing MTCT and the onward spread of HIV. For many women, particularly in resource-poor areas, pregnancy will be the only time in their young adult lives when they may access healthcare services on a regular basis. It is therefore an excellent opportunity for these women not only to be screened for HIV, but also to be educated and advised about HIV/ AIDS. Only women who know their HIV status before delivery can benefit from all these interventions. The antiretroviral treatment can suppress HIV, which is of great advantage to the health of the mother. The use of antiretroviral treatments can reduce the rate of prenatal HIV transmission by >70%; the risk may be further reduced by certain labour management techniques, and by avoiding breastfeeding. In this chapter we will briefly discuss the importance of antenatal screening for pregnant women, and the strategies used for treatment.