Left ventricular pseudoaneurysm, in which a ventricular free wall rupture is locally contained by adherent pericardium, is a rare complication of myocardial infarction. Compared w'th a true left ventricular aneunsm, a pseudoaneurysm has a greater propensity to sudden rupture, with catastrophic sequelae. Pseudoaneurysm may be surgically curable, a prompt and accurate diagnosis is thus essential. Transthoracic echocardiography has been the procedure of choice in the diagnosis of pseu- doaneurysm. Transesophageal echocardiography can provide more accurate information than transthoracic echocardiography for the evaluation of ventricular pseudoaneurysm located in posterior and inferior wall. We experienced a case of pseudoaneurysm of left ventricle in a 75-year-old female who presented with dyspnea. A large pseudoaneurysm of left ventricle vith narrow neck was de- tected by transesophageal echocardiography.