Hemichorea-hemiballism (HCHB) due to transient ischemic attacks (TIAs) is rare. An 83-year-old woman had repeated episodes of right-sided HCHB for 3 months. Magnetic resonance (MR) angiography demonstrated occlusion of the left carotid and middle cerebral arteries and severe stenosis of the innominate artery, and 24-h ambulatory blood pressure monitoring showed a blood pressure decrease of >20 mmHg after each meal. We speculated that HCHB developed as TIAs due to hemodynamic failure in the left cerebral hemisphere, caused by a combination of severe stenosis of the innominate artery concomitant with occlusion of the left carotid and middle cerebral arteries as well as postprandial hypotension.