The purpose of this article is to familiarize readers on the relationship between metabolic syndrome and periodontitis, as well as common pathogenetic processes underlying these diseases. The data of modern researches, devoted to the correlation of lesions of periodontal and systemic diseases associated with metabolic syndrome. In the article analyzed also the data of the original study of the interaction of periodontitis and metabolic syndrome, which also used special methods of examination like Doppler ultrasound microcirculatory vasculature of the periodontal tissues and ultrasound densitometry. The possible methods of diagnostics of a condition of periodontal tissues in patients with metabolic syndrome are considered. Conclusions about the relationship of each component of metabolic syndrome with periodontitis are made.