Objective: To compare, by ethnicity, the prevalence of HIV and zidovudine treatment among a cross-sectional survey of childbearing women in California in 1998, and the number of pediatric AIDS cases from 1998 to 2001. Methods: Blood specimens, collected via infant heel-stick for metabolic screening during the third quarter of 1998, were anonymously tested for HIV antibody. Positive specimens were subsequently tested for evidence of zidovudine therapy. Pediatric AIDS cases with diagnosis dates from 1998 to 2001 were obtained from the AIDS case registry. Results: Of the 119 108 specimens tested, 77 (0.65 per 1000) were HIV-antibody positive. Most (37.7%) of the 77 HIV-positive specimens were from newborns of African-American mothers, followed closely by Latina mothers (35.1%). The absence of zidovudine therapy was highest for Latina and African-American women, 29.6 and 24.1%, respectively. Latino and African-American children accounted for the majority of California pediatric AIDS cases diagnosed between 1998 and 2001. Conclusion: Innovative approaches are needed to increase the rate of zidovudine therapy among African-American and Latina HIV-infected childbearing women. These could include a shorter-course zidovudine regimen or rapid HIV testing and counselling of women in late-term pregnancy.