Phenolic phytochemicals are widely distributed in the plant kingdom. Regarding the protective effects on organisms, the polyphenol group is the most important. In different experiments, it has been shown that selected polyphenols, mainly flavonoids, possess protective effects on the cardiovascular system, as well as anticancer, antiviral and antiallergic properties. In coronary heart disease, the protective effects include mainly antithrombic, antioxidant, anti-ischaemic and vasorelaxant properties of flavonoids. It has been hypothesised that the phenomenon of a low incidence of coronary heart disease in French people may be partially related to the pharmacological properties of polyphenolic compounds included in red wine. Many epidemiological studies have shown that regular flavonoid intake is associated with reduced risk of cardiovascular diseases. This review article discusses the chemical structure of polyphenols and their beneficial properties in the cardiovascular system. (Fig. 1, Ref 74.).