BACKGROUND Hemiballismus is the most severe form of chorea and is a hyperkinetic disorder characterized by involuntary, high-amplitude movements of the ipsilateral arm and leg, due to lesions of the contralateral side of the central nervous system. Ischemic or hemorrhagic strokes and nonketotic hyperglycemia are predominant etiologies of hemiballismus. Case reports highlighting hemiballismus associated with temporal and parietal lobe infarcts have been published, although research of frontal lobe involvement is limited. CASE REPORT A 78-year-old woman presented to the Emergency Department with sudden-onset left-sided hemiballismus. On examination, she was alert, oriented to self and time, and able to follow commands. Her neurologic examination was notable for left-sided hemiballismus, described by the provider as periodic, uncontrolled, and involving a "flinging" motion of the left upper and lower extremities, sparing the face. She was treated with benzodiazepines in the Emergency Department and administered intravenous levetiracetam. Computed tomography of the head without contrast revealed an old left basal ganglia lacunar infarct. The patient was then admitted to the inpatient service, where magnetic resonance imaging of the brain revealed an acute punctate left superior frontal gyrus cortical infarct. Outpatient electroencephalogram revealed right anterior hemisphere dysfunction. CONCLUSIONS We describe a patient with left-sided sudden onset hemiballismus with an acute infarct of the ipsilateral superior frontal gyrus. This case highlights that brain lesions separate from the basal ganglia can induce hemiballismus, particularly within the frontal lobe, which warrants further research into precentral sulcus functioning and its role in modulating motor activity.