Twenty-five patients suffering from cerebrovascular pathology coupled with arterial pressure (AP) asymmetry in the brachial arteries underwent an analysis including studies of the clinical picture, angiographic and rheographic readings (REG and RVG of the forearms and hands). It is demonstrated that revelation of a steady and well-defined asymmetry of AP in the brachial arteries associated with pulse weakening or disappearance in the radial artery on the side of AP decrease combined with pronounced asymmetry of the RVG readings for the forearms and hands is an important diagnostic and prognostic sign that points to the involvement into the process (occlusion or stenosis) of the subclavian artery. As a rule, this is coupled with lesions of the other main arteries of the head and may provoke impairment of the cerebral circulation, occurring more frequently in the arteries of the vertebrobasilar system. The emphasis is laid on the importance and necessity of bilateral measurements of AP from the brachial arteries in patients suffering from cerebrovascular pathology.