Hemichorea can be the first clinical manifestation of an ischemic stroke, especially in the acute phase of a stroke, but hemichorea is extremely rare as a clinical manifestation of acute ischemic stroke and is easy to misdiagnose. Extending the therapeutic time window of intravenous thrombolysis and endovascular thrombectomy increases the likelihood of a bad clinical outcome. Herein we report a rare case of acute ischemic stroke with hemichorea as a clinical manifestation. A magnetic resonance angiography showed mild luminal stenosis of the anterior and middle cerebral arteries bilaterally and severe stenosis of the M1 segment of the right middle cerebral artery. A negative brain diffusion-weighted imaging-magnetic resonance examination may be related to a transient hypoperfusion of the subthalamic nucleus caused by severe stenosis of the right middle cerebral artery. In summary, the sudden onset of lateral limb choreiform movements cannot exclude the possibility of an acute ischemic stroke.