Introduction: Neonatal sepsis is a systemic infection usually caused by bacteria with consequences so severe that they can cause the death of newborns. In our country, neonatal sepsis varies from one hospital to another, being the second cause of mortality in newborns. Objective: The purposes of this study were to determine the incidence rate of neonatal sepsis, early and late neonatal sepsis, as well as the mortality rate and its association with gestational age and days of hospitalization in the Neonatal Intensive Care Unit of the General Hospital of Specialties "Dr. Javier Buenfil Osorio" of Campeche City. Material and Methods: A transversal, retrospective, observational, descriptive study was carried out that included all newborns that met the inclusion criteria, with a confirmed diagnosis of sepsis with or without added pathology, who were admitted at NICU of the hospital from January 2017 to December 2017. Results: During the period of study, 3800 neonates were born; which 373 neonates were included in this work. A total of 64 newborn were diagnosed with neonatal sepsis representing an incidence rate of 16.8 cases per 1,000 live births. Neonatal mortality rate associated with sepsis corresponded to 6.3 per 1,000 live births. In general, bacteria isolated from blood cultures were Klebsiella pneumoniae and Staphylococcus spp. Conclusions: This study found a high incidence rate of neonatal sepsis, being early sepsis higher compared with late sepsis. According to the acquisition time of neonatal sepsis, an association between the prematurity of newborn and late sepsis was demonstrated. Mortality of neonatal sepsis had a higher incidence with respect to the observed in neonates who died without diagnosis of sepsis. Longest stay in the NICU of premature newborn increased the risk of contracting a nosocomial infection in the hospital and dying.