Background: To provide, maintain and promote the health of children as a vulnerable group in the health service has a special place. So, the first step in reducing mortality and improve their health, identify causes of morbidity and mortality.

Materials and Methods: In this retrospective study, the main causes of neonate death in the case of neonatal who died in Aboozar hospital in 1390  were extracted, then based on the new international coding of diseases (International Coding Of Disease version 10) were categorized and the information on gestational age, type of delivery, birth weight, sex and age after birth .

Results: Five main causes of death were generally: prematurity, respiratory distress syndrome, sepsis, asphyxia and intracranial hemorrhage. It was also revealed that the causes of death in neonatal with low birth weight premature neonatal are similar and include: respiratory distress syndrome, sepsis, asphyxia and intracranial hemorrhage. In this study, between death and gestational age, mode of delivery, age after birth and birth weight there were a significant relationship   , but no significant relationship between the death and age.

Conclusion: While in this study infection as the primary cause of death in neonatal   , but important cause of mortality in preterm and low birth weight had no major difference with other studies.According to its ease and efficiency ICD10 and determine the underlying causes of neonatal mortality, neonatal death certificates this classification is recommended.