Objectives. To evaluate the rate of vertical transmission of HIV in southeastern Virginia for the past 7.5 years and to determine the impact of ZDV use as recommended by the CDC on the vertical transmission rate since July, 1994. Methods. A retrospective chart review was conducted to identify demographic, diagnostic, and ZDV use information in mother/infant pairs treated at a regional multidisciplinary maternal-child HIV clinic. A case was defined as an infant born to a known HIV infected mother between 1/1/88 and 8/31/95. Study children were stratified by the timing of exposure to ZDV: during pregnancy, during labor and delivery, and/or during the neonatal period. An infant was considered infected if one test detected HIV DNA by PCR after six weeks of age, and uninfected if there was one negative HIV DNA by PCR test after six weeks of age. Results. One hundred twenty-six children met study criteria. 54% were female and 46% were male. 86% were African American, 11% Caucasian, 2% Latino, and 1% American Indian. 18 of 24 (75%) infants born since July, 1994 received prophylactic treatment with ZDV as recommended. 3 of 18 (17%) were infected and 3 (17%) were indeterminant. 19 of 75 (25%) infants born with no perinatal ZDV exposure were infected (p =.13) and 3 (4%) were lost to follow-up. 2 of 20 (10%) infants with ZDV exposure only during pregnancy (p = 12); and 2 of 9 (22%) infants exposed at other times were infected. 15 of 43 (35%) infants were infected when the mothers' CD4 counts were <500 and 4 of 29 (14%) infants were infected when mothers' CD4 counts were >500 (p =.046).Conclusions. The HIV vertical transmission rate of 25% in our region was similar to the national experience. The vertical transmission rate of 17% despite prophylactic use of ZDV is higher than expected. Further study is needed to determine the impact of prophylactic ZDV on vertical transmission in HIV infected women with symptomatic HIV infection and to address problems with compliance in the treated population.