The number of HIV-infected pregnant women in the United States is steadily increasing. While seroprevalence rates vary widely by geography, as many as 2 to 5 per cent of pregnant women in epicenters are seropositive. Medical management of the HIV-infected woman during labor and delivery depends on the clinical stage of her disease. Many will be asymptomatic or mildly symptomatic and can be managed as usual. For others, delivery may be complicated by concomitant infections and AIDS-related conditions. Between 25 and 40 per cent of infants born to HIV infected mothers will acquire HIV infection. Transmission of HIV from mother to her infant can occur in utero, intrapartum, or postpartum by breastfeeding. Infants who escape intrauterine infection are exposed to HIV-infected maternal blood and secretions at the time of delivery. Precautions should be taken to minimize intrapartum exposure by removing blood and secretions from the surfaces and mucous membranes of the infant as soon as possible after birth. In addition, procedures that involve disruption of the infant's intact skin should be avoided when possible until maternal blood and secretions have been removed. The risk of nosocomial transmission of HIV is low (less than 1 per cent following needlestick exposure). Nevertheless, labor and delivery represent times when exposure to blood and body fluids can be anticipated. Precautions that are designed to prevent parenteral exposure and exposure of mucous membranes and nonintact skin of health care workers to blood and body fluids should be used routinely for all patients.