Heterosexual contact and intravenous drug use continue to result in new cases of human immunodeficiency virus type 1 (HIV-1) infection among adolescents and women of childbearing age. In North American and European surveys, 0.1% to 0.3% of childbearing women are infected with HIV; rates are 10 to 20 times higher in some inner-city areas. Timely, comprehensive, and well-coordinated care of the pregnant HIV-infected mother offers a unique opportunity to significantly influence two lives simultaneously. The mother can be offered therapeutic and prophylactic agents to treat her own infection, including antiretroviral therapy, which has been shown to markedly reduce the risk of vertical HIV-1 transmission. Recent advances in diagnostic virology now make it possible to definitively identify by 3 to 4 months of age those infants who are infected with HIV. Infants infected with HIV can be offered effective prophylaxis against Pneumocystis carinii pneumonia, which has dramatically reduced the incidence of this once common infection. Infected infants also should be monitored closely to institute antiretroviral therapy, and to diagnose and treat opportunistic and intercurrent infections and other acquired immunodeficiency syndrome-defining illnesses in a timely way.