A 49-year-old woman who had idiopathic thrombocytopenic purpura was admitted to our hospital with severe chest pain. Electrocardiography revealed inferolateral myocardial infarction. The patient underwent immediate coronary angiography, which revealed thrombi in the left coronary system. Percutaneous intervention was not indicated, because the thrombi had occluded the distal segments of multiple coronary arteries. Administration of tirofiban satisfactorily dissolved the thrombi.