The study demonstrated that patients having the baseline low arterial blood oxygen tension and high bronchial resistance showed the most unfavorable changes in the main integral values of gas exchange and hemodynamics on day 4 after pneumonectomy. Considerable progression of the obstructive syndrome, aggravation of arterial hypoxemia, significant rise of arterio-pulmonary blood pressure and perceptible drop of cardiac motor function are observed in these cases. The data may be used to predict gas exchange and hemodynamic disturbances in the early period after pneumonectomy.