A brief history of training of traditional birth attendants (TBAs), summary of evidence for effectiveness of TBA training, and consideration of the future role of trained TBAs in an environment that emphasizes transition to skilled birth attendance are provided. Evidence of the effectiveness of TBA training, based on 60 studies and standard meta-analytic procedures, includes moderate-to-large improvements in behaviours of TBAs relating to selected intrapartum and postnatal care practices, small significant increases in women's use of antenatal care and emergency obstetric care, and small significant decreases in perinatal mortality and neonatal mortality due to birth asphyxia and pneumonia. Such findings are consistent with the historical focus of TBA training on extending the reach of primary healthcare and a few programmes that have included home-based management of complications of births and the newborns, such as birth asphyxia and pneumonia. Evidence suggests that, in settings characterized by high mortality and weak health systems, trained TBAs can contribute to the Millennium Development Goal 4--a two-thirds reduction in the rate of mortality of children aged less than 14 years by 2015--through participation in key evidence-based interventions.