Brain oxygen supply in the residual period of ischemic stroke was studied in 25 patients with systemic atherosclerosis who had ischemic stroke in the basin of the right- or the left middle cerebral artery 1-13 years ago. The diagnosis was verified by multispiral computed tomography. All patients underwent duplex scanning of brachiocephal arteries with the measurement of vessel diameter and blood flow velocity. The venous component of the brain blood flow was evaluated by the data of bifrontal cerebral oxymetry. The greater volume velocity of arterial blood flow and reduced cerebral oxygenation were characteristic of the damaged hemisphere compared to the intact one. The analysis of cerebral vessel reactivity revealed that the index of vasomotor reactivity with the domination of vascular dilatation reserve was higher by 17-18% in the stroke hemisphere. Therefore, the indices of hemodynamics of arteries in the damaged hemisphere were compensatory higher compared to the intact hemisphere but the venous blood flow along the damaged hemisphere was lower due to the vascular dilatation. The asymmetry of vascular tone may be explained by the disturbance of mechanisms of autoregulation of cerebral blood circulation with the hyperfunction of the damaged hemisphere.