This prospective study, involving 76 pregnant women infected with HIV, paired with their 79 exposed infants, was carried out between May 1996 and October 2001, at the Reference Department for Pregnant Women Infected with HIV in Campo Grande, Mato Grosso do Sul. The mean age of the pregnant women was 24 years; 88% (67/76) apparently were infected due to sexual practices; 88% (67/76) were housewives; 823% (63/76) graduated from junior high school; 14.5% (11/76) reported co-infection with Hepatitis C, 9.2% with Syphilis; 51% (39/76) learned the diagnosis during prenatal care; 67% (51/76) reported HIV clinical symptomatology and 9.2% (7/76) reported opportunistic infections. Elective cesareans were performed in 57% (43/76). The mean gestational age at delivery was 38 weeks and we found 12.5% (10/80) pronatis; 97% (74/76) had a ruptured membrane time after less than four hours and one child (1.3%) was nursed. ACTG 076 Protocol (AIDS Clinical Trial Group 076) was used in 80% (61/76) of the pregnant women, with 100% adherence; 62% (38/61) used zidovudine plus another antiretroviral in the gestation; 92% (73/79) of the infants used zidovudine after the birth and 19% (14/73) used zidovudine and lamivudine. The transmission rate in this study was 2.5%.