Monitoring and evaluation is a critical component of effective management of prevention of mother-to-child transmission (PMTCT) programs. In the context of PMTCT, M&E plays the following roles: helps determine whether existing health services are adequately prepared for the introduction of PMTCT interventions; identifies gaps for the integration of PMTCT services into antenatal care and maternal and child health services; identifies weaknesses in the management information system (MIS) and tracking system of PMTCT services; provides guidance on ways to provide and maintain high-quality services; and supports implementation by providing ways to learn from experience, improve health activities, and promote better planning.