The objective of this study was to describe the epidemiological profile of precocious neonatal infant mortality in the city of Porto Velho, Rondonia. A quantitative, descriptive study with an ecological approach was carried out. The data source used was secondary, originating from the linkage between SINASC and SIM databases, from the Health Surveillance Agency of the Rondonia Health Department. For treatment, absolute frequency analyzes were performed. The neonatal infant mortality rate was 9.7 deaths per thousand live births, with a predominance of the preterm neonatal patient: 7.2 deaths per thousand live births. Of the deaths, 482 (72.8%) occurred in the precocious neonatal period (0 to 6 days) and 164 (24.7%) in the late neonatal 7 to 27 days of life. The findings indicate the need to improve the quality of health care services available in the city, both prenatal and obstetric care in the neonatal period.