Nowadays, advanced surgical and anaesthesiological techniques of coronary artery bypass grafting minimize the risk of severe complications in patients with advanced arteriosclerotic cerebrovascular disease. Nevertheless, in case of highly compromised cerebrovascular status, the decision whether to undertake coronary artery bypass grafting or not requires special patient-related consideration. A severe, unstable angina made it necessary to perform coronary bypass grafting in a patient with bilateral internal carotid occlusion, a bilateral mid-stage stenosis of both external carotid arteries, a diminished flow within the right vertebral artery, and a subsequently impaired intracranial blood flow. Intraoperatively, besides the usual hemodynamic measurements, laser-Doppler flow probes were placed on the left and right upper temple to monitor relative changes of the cerebral blood supply. Using an individual perioperative management, the patient experienced a normal postoperative course and was discharged in good condition.