Abstract
A 65-year-old woman presented with coughing and dyspnea. Giant left atrial myxoma was found by echocardiography. The tumor size was 7×5×4cm and its weight was 70g. The biatrial approach was chosen over left atriotomy or the transseptal approach. However, it may not be possible to decide on the correct incision line in cases of giant tumor. Intraoperative trans-esophageal echocardiogaphy was useful for evaluation of the mitral valve.