INTRODUCTION: Neonatal mortality is defined as the newborn children's number who die before they reach 28 days of life. Infant mortality rate in Mexico is 41% in the total deaths of under-five children. OBJECTIVE: To determinate the characteristics of neonatal mortality in an institutional hospital. SUBJECTS AND METHODS: A descriptive, retrospective and longitudinal study, of neonate's deaths from years 2008 to 2012 at our institution. We identified neonatal deaths by means of pediatrician's department records and we collected data from clinical files. We included only clinical records of neonates whose death occurred within the first 28 days of life and were attended at our institution. We excluded incomplete or lost clinical records. We studied gender, birth weight, gestational age, cause of death, co morbidity, prenatal care, history of neonatal death and gestational pathology. We carried descriptive statistics. RESULTS: Three-hundred and eight neonates' deaths total were studied; the age of gestation at birth was 30 ± 5 weeks (average and standard deviation), birth weight 1944 ± 990 g. The main cause of death was extreme immaturity 19% (58), followed by perinatal asphyxia with 13% (41). CONCLUSIONS: The main characteristics of neonatal mortality found in this study are similar to those reported in the literature, considering that extreme immaturity and prematurity are the characteristics in which higher mortality was present, we must have an appropriate prenatal control. [ABSTRACT FROM AUTHOR]