Nine patients with proved left ventricular pseudoaneurysm after transmural myocardial infarction were studied by two-dimensional echocardiography. In all patients two-dimensional echocardiography successfully displayed the pseudoaneurysm. The unique two-dimensional echocardiographic characteristics of pseudoaneurysm include: (1) a sharp discontinuity of the endocardial image at the site of the pseudoaneurysm communication with the left ventricular cavity, and (2) the presence of a relatively narrow orifice in comparison with the maximum diameter of the pseudoaneurysm fundus; visualization of the maximum diameter of the pseudoaneurysm fundus frequently required a slightly different tomographic view than that required for demonstration of the orifice. The distinctive echocardiographic features of pseudoaneurysm in these patients and technical implications for optimal visualization are described. Most of the pseudoaneurysms we encountered and many of those previously described were located posteriorly. We found the use of an inferior angulated view modified from the standard apical four-chamber view extremely helpful in detecting the orifice in patients with posterior or posterolateral pseudoaneurysms. We conclude that two-dimensional echocardiography is an important technique for diagnosis of left ventricular pseudoaneurysm.