Evidence from patients in the intensive care department of a multifield hospital treated for COVID-19 associated pneumonia with or without the use of a heated heliox mixture points to the beneficial effect of the mixture in the complex therapy of the disease. Comparative analysis of the clinical symptoms and laboratory data of the patients who received the heliox therapy and who did not (controls) testifies that heliox improves blood oxygenation, returns acid-base balance to normal, maintains dynamics of key pamaters positive and, therefore, increases effectiveness and shortens time of treatment.