COVID-19 is a disease that, in addition to respiratory failure, leads to thrombosis and bleeding due to coagulation disorders. Extracorporeal membrane oxygenation (ECMO), required in cases of a deterioration of gas exchange function of the lungs, contributes to changes in blood coagulation indicators, which leads to an increased risk of hemorrhagic complications and thrombosis. In the article, a clinical case of a severe course of COVID-19 is reported, which required ECMO. During the treatment, antithrombin-III was used, which allowed avoiding life-threatening complications and successfully completing the procedure.