Objectives: To assess maternal mortality in Rio Grande do Norte, in the series 2003-2008, data from the Mortality Information System (SIM) and the Committee on Maternal Mortality (MMR) of the state. Methods: A descriptive study of population-based data on maternal mortality secondary collected by the SIM state through the program Tabwin, version 3.2, and CMM-RN, through the records and file reports. Results: We found that the percentage of maternal deaths investigated and confirmed by the Committee in relation to the registered on SIM ranged from 3% in 2003, decreasing to 1% in 2007, which is very small compared to total deaths of women in childbearing age in the period studied. Conclusions: It is possible to perceive weaknesses of the epidemiological surveillance of maternal deaths in the screening and a performance of the Committee in investigating these deaths far below those recorded in the on SIM, showing underreporting, data incompleteness and lack of consistency in the flow of information between these banks, making it impossible to compare the existing information. It is suggested that the Ordinances No. 1172/2004 and No 1119/2008 of the Ministry of Healthcare have to be complied, that surveillance supervises the registration of maternal death as an event of compulsory notification and that a punitive effect for municipalities that fail to comply with this protocol is established . These measures will help to reduce maternal mortalit