Purpose of study. Identification of significant laboratory markers for the development of atherosclerosis (AS) of the carotid arteries (CA) in patients with obstructive sleep apnea syndrome (OSAS).Materials and methods. 152 male patients were examined, 84 of whom, according to polysomnography (PSG), were diagnosed with OSAS. Diagnosis of AS CA was performed by triplex scanning. The complex of laboratory studies included the assessment of lipid metabolism, the concentration of highly sensitive C-reactive protein (hsCRP), interleukin‑1β (IL‑1β), interleukin‑6 (IL‑6) and interleukin‑10 (IL‑10) in blood serum.Results. In patients with OSAS, a statistically significant increase in the complex of proatherogenic factors was found: hsCRP, pro-inflammatory cytokines, ratio of apoproteins and atherogenic coefficient compared with patients without OSAS despite the absence of differences in the severity of atherosclerotic lesions of the carotid arteries in these groupsConclusion. The development of OSAS is associated with severe lipid metabolism disorders and activation of nonspecific inflammation, which determines an increased risk of atherosclerosis in this group of patients.