Background Neonatal mortality rate is one of the main indicators of health care systems in each country. The first step in improving the level of these indicators is to identify the causes of neonatal dead and its related factors. In this study, the causes of neonatal mortality and its related factors in neonatal intensive care unit at Imam Reza hospital were investigated. Materials and Methods A descriptive cross sectional study was carried out from 2014 to 2016, on all neonates who died in neonatal intensive care unit of Imam Reza Hospital in Kermanshah city, Iran. Information about the infant, mother and the causes of mortality of the infant were collected from hospital records of neonatal care unit and families and physician of infants. Then data was recorded in the data collection form and analyzed using SPSS version 18.0 software. Results In this study, 566 newborns (19.2%) died of 2,946 hospitalized infants. The most common causes of death was respiratory distress syndrome 190 (33.6%), and sepsis 128 (22.6%); 95.5% of neonatal deaths occurred at gestational age below 37 weeks, and 81.6% in birth weight less than 2,500gr. Also, 452 cases (79.9%) had deaths during the first week after birth, and the highest deaths 274 (48.8%) were in the night shift (P<0.001). Conclusion According to the results of this study, the most common causes of neonatal death were prematurity (gestational age below 37 weeks), respiratory distress syndrome and sepsis. Most dead neonates have a weight below 2,500 grams. The highest death rate occurred in the first week of birth and in the night shift.
