The review presents role of myeloperoxidase (enzyme secreted by leucocytes) in the development of ischemic heart disease. Myeloperoxidase is mostly contained in neutrophils – basic cells of innate immunity, making about 5 % of cell volume. The physiological function of myeloperoxidase consists in elimination of microorganisms and forming high-reactive agents. Oxidative stress of neutrophils in reply to pathogens associated with changes of lipid metabolism is directed at neutralization of endotoxins’ toxic effect. Products reactions catalyzed by myeloperoxidase are strong oxidants (in particular, hypochlorous acid), reactive derivates of nitrogen and free radicals, initiator of lipids oxidization and causing modification of proteins. Myeloperoxidase is quickly absorbed on-the-spot of LDL, forming oxidized lipoproteins able to provoke many atherogenic processes. The target of myeloperoxidase is also apolipoprotein A1 HDL. References regarding role of myeloperoxidase in plasma and neutrophils of peripheral blood at different manifestations of ischemic heart disease, as well as results of experimental works are provided.