This study aimed to evaluate the impact of invasive devices as risk factors for the development of neonatal sepsis in Neonatal Intensive Care Units. Hospital-based retrospective cohort study performed in two Neonatal Intensive Care Units in Ponta Grossa, Paraná, Brazil. Documentary data were collected through consultation of electronic medical charts of all patients admitted to two hospitals and of the patients with diagnosis of sepsis in another hospital. Health conditions at admission and outcomes were evaluated. Frequencies of the reasons for admission and the outcomes were calculated. In the association analysis, exposure variables were calculated with odds ratio and confidence intervals (95%). The frequency of sepsis was 39%, and 45.7% of the cases were of early-onset sepsis and 54.3% of late-onset sepsis. The mortality rate associated with sepsis was 9.9%. The use of invasive devices was observed to increase by 6 times the risk of neonatal sepsis. Peripherally inserted central catheter and phlebotomy were the devices causing higher risk. The high incidence of late-onset sepsis, its association with the use of invasive devices and the higher mortality rate among newborns with sepsis suggest the presence of fragilities in neonatal care and the need to seek alternatives of neonatal approach to avoid new cases of neonatal sepsis and consequent death.