Antiretroviral drugs are primarily used to treat people living with HIV but can also reduce the risk of transmission. The first application of this prophylactic approach was in the prevention of mother-to-child transmission, which comprises three components: 1) antiretroviral therapy during pregnancy to reduce maternal viral load, 2) pre-exposure prophylactic treatment of the fetus in utero and intrapartum, and 3) postexposure neonatal treatment. This has resulted in a sharp reduction in mother-to-child transmission, to well below 1 % in France today. "Treatment as prevention" (TASP) is now widely recommended to prevent sexual transmission to partners of people living with HIV articularly when a couple wishes to have children. Achieving and sustaining undetectable viral load is an important means of reducing the risk of sexual transmission in serodiscordant couples and also of controlling the pandemic worldwide. The other uses of antiretroviral drugs to protect HIV-negative people at risk include post-exposure prophylaxis (PEP) and pre-exposure prophylaxis (PrEP). Prevention has both individual and collective dimensions and involves several components, including behavioral changes, serological testing, and use of antiretrovirals.