Background: Hyperkinetic disorders such as hemichorea can be caused by cerebrovascular, infectious or inflammatory diseases or by metabolic conditions such as hyperglycaemia. Hyperglycaemic hemichorea is a rare movement disorder which is frequently misdiagnosed. It is characterized by involuntary, continuous, non-patterned movements on one side of the body, basal ganglia lesions seen on head CT or MRI, and clinical improvement after blood glucose normalization. We describe the case of a female patient with uncontrolled diabetes who presented with hemichorea. Case presentation: We report the case of a 69-year-old woman with type 2 diabetes who presented with abnormal movements of the right upper limb. She had no neurological signs other than hemichorea. Her blood glucose level was 349 mg/dl and her glycosylated haemoglobin level (HbA1c) was 10.5%. Head CT and MRI showed no changes in the basal ganglia or ischaemic lesions. The patient was started on insulin and haloperidol with clinical improvement. Conclusion: Larger case series are needed to establish better understanding of the physiopathological mechanisms and diagnostic criteria of hyperglycaemic hemichorea. The most important diagnostic criterion is clinical improvement after glycaemic control.