Introduction: Brachiocephalic artery stenosis rarely causes right hemispheric infarction with associated left hemiparesis. To date, there have been no reported cases of stroke associated with brachiocephalic artery stenosis that were successfully treated with recombinant tissue-type plasminogen activator (rt-PA), alteplase.Case Report: An 80-year-old woman presented with left hemiparesis. Brain computed tomography showed no hemorrhage, and computed tomography angiography demonstrated brachiocephalic artery stenosis. Alteplase was administered based on a diagnosis of ischemic stroke. Brain magnetic resonance imaging showed multiple acute infarctions. Thereafter, the blood pressure of the right arm was found to be lower than that of the left arm. The patient’s neurological deficits gradually improved; she was eventually able to walk again and was thus discharged home.Conclusion: While the combination of left hemiparesis and a decrease in blood pressure in the right arm are well known in patients with stroke associated with Stanford type A aortic dissections, it may also occur in patients with stroke due to brachiocephalic artery stenosis. Unlike stroke associated with Stanford type A aortic dissections, stroke due to brachiocephalic artery stenosis may be treated with alteplase.