Aim. To study the effect of cytoflavin on parameters of acid-base blood balance in acute myocardial infarction. Material and methods. 46 patients with standard therapy received the drug cytoflavin (Polysan, St.Petersburg, Russia) intravenously 20 ml of the solution diluted in 250 ml 5% glucose solution, 2 times a day for 30 minutes before and 12 hours after coronary artery recanalization; 60 patients (control group) received only standard therapy. The drug’s effectiveness was evaluated by the content of metabolites (glucose, lactate) and indicators of the acidic state of the blood: the partial pressure of gases, the level of oxyhemoglobin, carboxyhemoglobin, oxygen transport function of blood. Results. The introduction of cytoflavin to patients promoted increase in oxygen partial pressure by 18%, oxyhemoglobin level by 6%, decrease in carboxyhemoglobin by 25%, positive dynamics of oxygen transport function of blood compared to the same indicator in the patients of the control group. Addition to standard therapy with cytoflavin significantly reduced the level of glucose in patients with acute myocardial infarction on 24 hours after coronary artery recanalization for 20% relative to the control, the lactic acid — 57%. Conclusion. The inclusion of cytoflavin in the treatment of patients with acute myocardial infarction should be considered as pathogenetically justified clinically justified and promising.