The authors report the case of a 49 year old man referred for a preoperative evaluation of a left atrial myxoma. During the hospital admission, the patient had an episode of sudden anginal chest pain associated with electrocardiographic changes of anteroseptoapical myocardial infarction. Emergency coronary angiography showed occlusion of the middle segment of the left anterior descending artery whereas it had been absolutely normal on the coronary angiogramme performed a few days beforehand. The diagnosis of coronary embolism from the left atrial myxoma was made and an emergency coronary angioplasty was performed followed by surgical ablation of the tumour.