Hemiballism and hemichorea are recognized manifestations of cerebral infarction. Paroxysmal dyskinesias are less well recognized symptoms of transient cerebral ischemia. We describe a 41-year-old man with distal internal carotid artery occlusion and poor intracranial collaterization who developed repetitive stereotyped involuntary arm movements and subsequent cerebral infarction. This peculiar manifestation of transient cerebral ischemia may indicate poor intracranial collateralization with reliance upon leptomeningeal collaterals. Earlier recognition may help avert cerebral infarction.