This report describes a 52 year-old women with an inferior myocardial infarction due to a coronary artery embolus. Coronary angiography revealed occlusion of right coronary artery and echocardiographic findings showed a large left intraatrial tumour. The tumour was removed surgically and pathological findings confirmed the diagnosis of myxoma. Aetiology of the occlusion was closely related to the left atrial tumour. Myocardial infarction was the first manifestation of left atrial myxoma.