Finding the root causes of maternal mortality plays a significant role in identifying the status of development in the society and in expressing the current situation of maternal health and the adoption of appropriate measures towards its improve­ment. With the above in mind and for the purpose of fulfillment of objectives and national and international commitments, the National Maternal Mortality Surveillance System was designed in 2000 and implemented from 2001 through out the coun­try in Iran. Implementation of this program aimed at identifying the factors contributing to maternal mortality during prena­tal, delivery and postnatal periods through discovering the process that each mother has followed until her death, identify­ing avoidable causes of death and designing interventions in order to solve problems and prevent occurring of simi­lar deaths.