Circulation in the lower limbs of 22 patients with obliterating arteriosclerosis of the aorta and main arteries was studied during operation by means of occlusion plethysmography and from the results of manometry and flow measurement. All patients underwent reconstructive operations on the vessels. Ejection of blood into the limb with a large volume of the contributing vascular bed was encountered immediately and in the first few days after the operation; the specific blood flow (ml/min/100 cm3 tissue) sharply increased in the limb most affected by ischemia. Circulation in the lower limbs was gradually normalized by the 5 th--7 th day. Some indices obtained during the study are important for understanding the course of the postoperative period in patients with the pathological condition discussed.