Aim. To study various aspects of cerebrovascular diseases (CVD) in the presence of metabolic syndrome (MS). Subjects and methods. A comprehensive clinical, laboratory, ultrasound, and neuroimaging study was conducted in 514 patients with symptomatic and asymptomatic atherosclerotic lesion of the internal carotid artery and MS. Results. MS was found and proven to affect the following factors: a) the course and progression of carotid artery (CA) atherosclerotic lesion with transformation of its asymptomatic to symptomatic state; b) the structure and instability of an atherosclerotic plaque; c) the magnitude of blood rheological changes; d) endothelial dysfunction; e) white matter changes; f) the clinical features of both acute and chronic CVD and the development of cognitive impairments. Conclusion. The association of the atherogenic activity of major components of MS, such as hyperinsulinemia, hypertension, dyslipidemia, and obesity, in the presence of dysregulated hemostasis and blood rheology substantially increases the risk of a progressive CA atherosclerotic process even in its asymptomatic course and accordingly favors the development and progression of different manifestations of CVD.