The economic burden of early-onset neonatal sepsis (EONS) is currently uncertain in Russia. OBJECTIVES: To evaluate economic burden of EONS and mortality in the Russian Federation, including both direct and indirect costs. METHODS: Chosen methodology was based on the analysis of the sample of medical records from neonatal intensive care units (NICUs). Neonates (n=79) were classified according to gestational age (GA). Direct costs were calculated based on the data about resource consumption in real prectice. Indirect costs included underproduced contribution to GDP due to premature death and morbidity, resulting from disease, welfare and care payments, comprising disability support pensions. RESULTS: Mean cost of hospitalization to NICU (direct costs) per infant with EONS is estimated as € 9,092. Mean direct costs for hospitalization per extremely-low-birth-weight (ELBW) infant are twice higher in comparison with mean direct costs per infant with GA ≥30 weeks of gestation (€ 21,056 per ELBW infant and € 11,938 per infant with GA ≥30 weeks of gestation). Total underproduced contribution to GDP is estimated as € 152,254 (87% of total costs) per infant with EONS, welfare and care payments, comprising disability support pensions - € 14,721 (8%) per infant. Thus indirect costs account for 95% of expenditure. Total costs associated with EONS are estimated as € 176,067 per infant. CONCLUSIONS: Improvement of treatment of EONS may play the crucial socio-economic role since it could significantly reduce the economic burden of the disease for the Russian Federation.