We present a case of inferior-wall myocardial infarction associated with thrombi in both the right ventricle and right atrium. Routine transthoracic echocardiography could not detect these thrombi while transesophageal echocardiography provided an excellent image of the thrombi. The right atrium or right ventricle may be the site for thrombi, presumably due to both right ventricular and right atrial infarction in acute inferior-wall infarction.