1. In patients with chronic cor pulmonale there is a regression dependence between the amount of exercise-induced increase in pulmonary arterial pressure and the level of resting value. 2. Hemodynamics during exercise are influenced by the patient's position in a certain degree. 3. The exercise-induced increase in pulmonary arterial pressure in chronic cor pulmonale is not influenced by the patient's age. 4. The time course of pressure fall during recovery depends on the amount of pressure increase during exercise, it depends less evidently on the level of the resting values. 5. Tachycardia is not a compulsory symptom of chronic cor pulmonale.