Neonatal sepsis (NS) is the leading cause of morbidity and mortality in intensive care units. The issue of early diagnosis of a purulent-septic process in newborns using modern research methods that can be used as screening methods for verifying the diagnosis remains relevant. Objective. To conduct a comparative analysis of clinical and laboratory features of the course of early and late neonatal sepsis to optimize the early diagnosis of infectious-inflammatory process at the stage of obstetric institutions. Material and methods. To achieve this goal, retrospectively 26 medical records of newborns at the stage of obstetric institutions were analyzed, which were later transferred for treatment to the Regional Municipal Non-Profit Enterprise "Chernivtsi Regional Children's Clinical Hospital" in Chernivtsi with manifestations of generalized infectious-inflammatory process. The first group consisted of 14 (53.8%) newborns diagnosed with early neonatal sepsis; the second group included 12 (46.2%) newborns that were diagnosed with late neonatal sepsis (p > 0.05). Research results. Peculiarities of the clinical manifestation of the infectious-inflammatory process should be recognized as a combination of several locus of infection, which occurred in group I in 57.1% of cases, in group II – in 16.6% of cases (p < 0.05). Muffled heart sounds at the initial examination and a tendency to thermolability were more common in newborns with early NS: OR – 6.1 (95% CI 2.71–13.92), RR – 1.97 (95% CI 0.97–3.97), AR – 0.39 and OR – 3.6 (95% CI 2.01–6.46), RR – 1.89 (95% CI 1.38–2.58), AR – 0.31. Conclusion. The analysis revealed that in early neonatal sepsis the risk of detecting muffled heart sounds during auscultation (odds ratio – 6.1), unstable body temperature (odds ratio – 3.6) and absolute leukocyte count > 20.0×109/L is significantly higher (odds ratio – 2.79).