In the last two decades, private providers have become an important source of health care in Latin America, and yet, there is little documentation concerning its effectiveness in providing basic public and preventive health services. We use Demographic and Health Surveys from six Latin American countries to compare the effectiveness of the private versus public sector in providing basic health interventions such as prenatal care. We find that the number of prenatal visits is higher in the private sector, but this is not associated with higher birth weight. We discuss different strategies to improve the role of private providers. © 2010 Elsevier Ltd.