Delayed ischemic deficits from vasospasm after subarachnoid hemorrhage remain a major source of death and disability to patients surviving subarachnoid hemorrhage. Ideal treatment for this condition would prevent or reverse spasm in major subarachnoid vessels. This goal remains elusive. Considerable success has been obtained with augmentation of flow in ischemic regions by induced hypertension and hypervolemia. Some patients are not good candidates for this therapy because of underlying cardiovascular disease or the presence of unsecured aneurysms. A total of 11 patients have recently undergone extracranial-intracranial bypass for the treatment of symptomatic vasospasm. Bypass was performed in 4 patients due to failure of medical management and in 7 patients due to our reluctance to induce hypertension in the setting of unsecured aneurysms. Eight of the 11 patients responded neurologically to the bypass procedure within 24 hours. In 6 cases, neurological deficits either improved or resolved. After operation, all 8 patients maintained their preoperative neurological status with lower mean arterial blood pressures than before bypass. Noncomatose patients with focal middle cerebral ischemic deficits and secured aneurysms in whom medical management has failed or in whom these measures are contraindicated may indeed benefit from extracranial-intracranial bypass. Patients with unsecured aneurysms remote from an ischemic middle cerebral territory should probably be revascularized if cautious hypertension fails to improve their conditions.