Metabolic syndrome is a set of metabolic disorders that are necessarily always manifested together. They increase the risk of cardiovascular disease, type 2 diabetes, non-alcoholic fatty liver disease and polycystic ovary syndrome. The disorders that make this condition are abdominal obesity, hypertension, atherogenic dyslipidemia, high blood glucoselevels and insulin resistance. In order to determine a diagnosis of metabolic syndrome it is necessary to confirm the existence of at least three disorders. Inflammatory diseases of periodontal tissues are divided into gingivitis, where inflammation is confined to the gingiva, and periodontitis where other, deeper periodontal structures are affected. The connection between periodontal disease and metabolic syndrome is a mild, systemic inflammation. In metabolic syndrome, the cause is in visceral fatty tissue that secreteexcessive pro-inflammatory cytokines and bioactive products, while periodontal diseases are caused by microorganisms. Pro-inflammatory cytokines from infected periodontal tissues circulating in blood can affect each of the components of metabolic syndrome and vice versa. Higher incidence, more pronounced, as well as faster and more progressive course of both inflammatory changes in periodontitis in people with metabolic syndrome certainly confirms the existence of a connection between them.