Summary The main objective of this paper was to know the importance of maternal deaths in 2004 in the city of Belem, capital of the State of Para. All the cases of deaths involving women living in Belem-PA who were in their reproductive age were investigated and as a result it become possible to analyze the quality of the Mortality Information System (SIM) used in the analysis concerning the events being studied. The outcomes of the analysis revealed a high percentage of avoidable deaths (78.6%), in which most of the cases were related to direct obstetric causes (92.8%). The maternal mortality ratio was 45.0/100,000 new born, with a 50% reduction in the records of maternal death in the SIM, in which occurred a correction factor of 0.85. This difference can be explained due to the fact that SIM had registered non-confirmed maternal deaths in the study. It was possible to conclude that only the investigation of these death cases and the follow up of the SIM’s work are able to qualify the information and provide proper basis to create new heath policies aiming at the reduction of maternal death.