Naloxone, an opiate antagonist, has recently been reported to temporarily reverse neurologic deficits associated with subarachnoid hemorrhage. To determine if this unexpected effect of naloxone might also occur in other forms of cerebrovascular diseases, 13 patients who presented with acute neurologic deficits were administered intravenous naloxone. In 3 of these patients, coincidental improvement in neurologic status was seen. In one patient the improvement was permanent. Ten of the 11 patients with non fatal neurologic damage improved later in their hospital course - 7 of them to their pre-admission state. The only side effect noted was the temporally related onset of a single focal seizure in an ethanol intoxicated patient with an intracerebral hemorrhage. Stroke Vol 15, No I, 1984