Tuberculosis (TB) is the preeminent manifestation of HIV infection and has become a leading cause of maternal mortality and morbidity in high HIV-prevalence settings. Active TB in pregnant women has potentially serious consequences for fetuses and newborns. In Soweto, South Africa, there is a more than 90% uptake of voluntary counseling and HIV testing during routine antenatal care, and almost one third of pregnant women are HIV-infected. The posttest counseling session of the prevention of mother-to-child transmission program provides an opportunity to screen HIV-infected pregnant women for TB. In this study, 370 HIV-infected pregnant women were screened for symptoms of active TB by lay counselors at the posttest counseling session. If symptomatic, they were referred to nurses who investigated them further. Eight women were found to have previously undiagnosed, smear-negative, culture-confirmed TB (2160/100,000). The mean CD4 count in those with active TB compared to those without TB was 276 × 106 cells per liter vs 447 × 106 cells per liter (P = 0.051). Symptoms most associated with active TB were hemoptysis and fever. We conclude that rates of TB in HIV-infected pregnant women are high, and screening for TB during routine antenatal care should be implemented in high HIV-prevalence settings.