This article reviews critical aspects that have had an impact on the implementation of epidemiological surveillance of Extreme Maternal Morbidity (MME, for its initials in Spanish), as a tracer event of quality maternal care at population and institutional level; taking into account that maternal mortality has been usually monitored, and its analysis allows interventions to avoid maternal death. Until 2015, very few countries had been able to meet the goals established in the Millennium Development Goals (MDGs), especially MDG 5 - improving maternal health. As of today, it is observed that maternal mortality rate is quite heterogeneous, with rates from 1 case per 100,000 live births in developed countries, to more than 100 cases per 100,000 live births in developing countries. Therefore, complementary strategies such as surveillance of the MME could offer a more effective alternative to identify and implement interventions that allow us to prevent mortality and strengthen the quality of obstetric care. In addition, the importance of MME as a quality tracer event is that, unlike what is observed with maternal mortality, this is an event that occurs more frequently, is anticipatory of death, and the surviving pregnant woman is the primary source of information.