Hemiplegia is a rare complication accompanied with hypoglycemia. We reported three cases of hypoglycemic hemiplegia (HH). Case 1: A 74-year-old female had medication for diabetes mellitus (DM). She had right hemiplegia and aphasia. Case 2: A 72-year-old male had DM, and was admitted to our hospital having loss of consciousness and right hemiplegia. Case 3: An 82-year-old female suffered from consciousness disturbance with tetraplegia, and had left hemiparesis later. She had no DM, but suffered from iatrogenic hypoglycemia. The brain CT of these three cases showed atrophy, and MRI demonstrated multiple infarction. The angiography of case 1 showed the stenosis of bilateral internal carotid artery and the origin of the left vertebral artery. The angiography of case 2 showed severe stenosis of the left internal carotid artery. The cases above had hypoglycemia at admission. The value of the case 1 was 48 mg/dl, case 2 was 35 mg/dl and case 3 was 38 mg/dl. But these symptoms of the three cases disappeared rapidly after glucose infusion. The literature regarding HH was reviewed, and the pathogenesis was discussed. We emphasize the importance of checking blood sugar levels for the emerging patients with hemiplegia, because it is difficult to discriminate by clinical history or neurological findings.