There are few documented experiences of HIV-infected pregnant women receiving highly active antiretroviral treatment (HAART) in resource-limited settings. The authors evaluated the short-term and long-term effectiveness of a two-tiered strategy of prevention of mother-to-child transmission of HIV (PMTCT) in Africa. Women meeting eligibility criteria received HAART, while women with less advanced HIV disease received short-course antiretroviral PMTCT regimens.