Ballismus, also known as hemiballismus, refers to a rare condition that causes random body movements, including extreme flailing ballistic movements. Although there are several causes, the most common are stroke, traumatic brain injury, nonketotic hyperglycemia, and amyotrophic lateral sclerosis. Thankfully rare, this condition occurs at a rate of around 1 in 2,000 stroke patients. For treatment, the practitioner must ascertain and treat the underlying condition. Other treatments include anticonvulsants, antipsychotic medication, and neurosurgery.