We studied the effect of deproteinized hemoderivative of calf blood, thioctic acid and vinpocetine with piracetam on the endothelial function in patients with chronic cerebral ischemia stage III. After pharmacological treatment, there was the improvement in the endothelium properties of both large and small blood vessels. The index of occlusion that characterized the function of small vessels reached normal values while the phase shift did not approach to the reference values. This notion indicates that in cerebral atherosclerosis small arteries initially are subject to alterations to a lesser extent compared to the arteries of large and medium caliber. The most effective medicines of those used for the correction of endothelial dysfunction are deproteinized hemoderivative of calf blood and thioctic acid.