We herein report a case of hemichorea-hemiballism in an 85-year-old man diagnosed with diabetes at 76 years of age. After a one-year interruption in treatment, he was treated with a low-calorie diet, linagliptin, and nateglinide. Over 51 days, his HbA1c level decreased from 15.8% to 7.7%. After a prompt improvement in his hyperglycemia, he began experiencing involuntary movements in the right u...