Giant cell arteritis occurs mainly in the cranial arteries, especially in the temporal area, and rarely in the coronary arteries. Here, we present a case of coronary artery giant cell arteritis in a 51-year-old woman who complained of atypical chest pain. Radionuclide angiography showed dilated left ventricle with global hypokinesia. Despite medical treatment, she suffered progressive heart failure and finally was given a heart transplant. The pathologic examination revealed myocardial infarction due to coronary giant cell arteritis. Unusual giant cell arteritis should be considered in the differential diagnoses of myocardial infarction.