Non-bacterial osteomyelitis (NBO) is an immuno-inflammatory disease associated with a cytokine imbalance. Objective of the research: to quantify pro-inflammatory and anti-inflammatory cytokines in patients with NBO, compare them with similar indicators of healthy children and with known clinical and laboratory indicators of NBO activity. Materials and methods: the study included 42 children with NBO in the active stage [onset age – 4 (2,9; 9,9) years] and 30 healthy children of comparable age and gender, who did not suffer from acute intercurrent diseases for 3 months preceding the study. The number of bone inflammation foci, their localization and inflammatory activity parameters (ESR, CRP) were evaluated in all patients. Blood plasma cytokines levels: protein 14-3-3η, protein S100A8/A9, interleukin-6 (IL-6), interleukin-18 (IL-18), interleukin-4 (IL-4), interleukin-17 (IL-17), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) by enzymelinked immunosorbent assay were analyzed in all studied patients. Results: in patients with NBO, the levels of all studied cytokines were increased compared with healthy children. The discriminant analysis showed that IL-6 (p=0,0001), IL-18 (p=0,012), IL-4 (p=0,049), IL-17 (p=0,0001), IL-1β (p=0,0001) and TNF-α (p=0,002) are associated with NBO. Axial skeleton lesions were accompanied by a statistically significantly higher level of IL-1β compared with the involvement of the peripheral keleton only: 51,2 (45,8; 52,3) pg/ml and 45,8 (40,3; 50,8) pg/ml respectively (p=0,034). There was no statistically significant relationship between studied biomarkers and routine parameters of inflammatory activity — ESR, CRP, number of bone foci, fever. Conclusion: the study confirmed the role of cytokine imbalance in NBO pathogenesis, which necessitates studying the role of specific cytokines as biomarkers and potential therapeutic targets of differect NBO variants.