Hemichorea has been reported as a rare complication of nonketotic hyperglycemia. We report a diabetic patient who developed paroxysmal hemichorea. When hyperglycemia is corrected, the movement disorder resolves within a few days. The MR images showed high signal intensity on T1-weighted images and low signal intensity on T2-weighted images in the left basal ganglia contralateral to the involuntary movement. We present a case of hemichorea in a poorly controlled diabetic patient.