was to study the effect of 2-ethyl-6-methyl-3-hydroxypyridine malate (Ethoxidol) on the concentration of oxidative stress metabolites in patients with chronic heart failure (CHF) and hypertension. 126 patients with FC I-III CHF have been examined. In addition to their individual therapy these patients received intravenous infusions of Ethoxidol. Blood content of 2,3-diphosphoglycerate (2,3-DPG), oxygen tension (рО ), pH, concentration of total peroxides, lactate, and aldosterone were identified. 2,3-DPG levels (g/L erythrocytes) in whole blood samples were determined by an enzyme assay using the reagent kit (Rosh, Germany), values of рО , рСО , рН, lactate in the venous blood were measured using gas analyzer Stat Profil pHOx Ultra (Nova Biomedical, USA). Indices of oxidative stress, i.e. the concentration of plasma total peroxides, were investigated by ELISA using OxyStat kit (Biomedica, Austria). Peripheral venous blood samples were collected from all patients before and 6 days after the daily intravenous Ethoxidol infusion. In patients with FC I, II, III CHF, on day 7 after intravenous Ethoxidol infusion at a dose of 100 mg/day, statistically significant growth (p=0.0002) of PaO level by 15.7, 17.4, and 22.8%, respectively, was noted. In patients with FC I, II, III CHF in the group receiving standard therapy, statistically significant (p=0.002) reduction of 2,3-DPG level by 2.7, 2.4, and 4.0%, respectively, was registered. On day 7 after the infusion of Ethoxidol at a dose of 100 mg/day, its decrease by 5.7, 10.5, and 26.2%, respectively (p<0.0001), was also observed. The increased concentrations of active oxygen forms have been established to negatively affect various bodily functions and adversely influence the pathophysiology of numerous diseases. Application of antioxidants, including Ethoxidol presented by us in this article, may become a clue to the development of preventive measures for many serious diseases.