摘要:Background: Well-functioning health systems and effective preventive measures require registering the exact number and valid data of fatal injuries. The present study aimed to determine the completeness of fatal injuries reported by LMO with the use of the capture-recapture method and finding the reasons for those unregistered fatal injuries in Hamedan County. Methods: This cross-sectional study was conducted in Hamadan County from 22 August 2015 to 21 August 2016. The completeness of fatal injuries reported by LMO, as the main source of fatal injuries was estimated with the employ of the capture-recapture method including Health Department and Police. Log-linear modeling was used for statistical analysis. The number of fatal injuries that probably had not been detected in any three sources was estimated by using the GENLOG command. Results: A total of 451 fatal injuries were registered in LMO for one year. The registries were included different amounts of detailed information from at least five variables in the Emergency Medical System (EMS) up to all detailed information in the LMO and Health Department. More fatal injuries occurred in males than females at all ages and the two-sex difference spectrum was wider between about 20 to 45 years old. Among cases of LMO, we found 29 unreported deaths. Therefore, the completeness of reported fatal injuries by LMO was estimated to be 86.9%. Conclusions: Fatal injuries are under-reported by the main source of this type of death in Iran. Identification of fundamental causes, integrated death registry system, and using a standard cause of death classification are needed to promote the registration of fatal injuries.