The purpose of this study was to assess the relative diagnostic value of two-dimensional echocardiography (2D-Echo) and biplane left ventricular cineangiography (CV) for detecting the presence of left ventricular mural thrombi (LVT) in selected patients (pts) with left ventricular aneurysm (LVA). The Echocardiographic and Angiographic data of 19 pts selected from a group of 58 pts with coronary artery disease who underwent surgery for aorto-coronary bypass and/or aneurismectomy, were retrospectively examined. The presence of LVA was shown at surgery in all patients, located near the cardiac apex in 10 pts, at the level of the antero-septal wall of left ventricle in 7 pts and of the antero-lateral wall in 2 pts. In 11 of the 19 pts (57.9%) a LVT was identified at surgery. The thrombus was large (greater than 2 cmq) in 6 pts and small (greater than 2 cmq) in 5 pts. In 10 of the 11 pts with LVT 2D-Echo showed the thrombus prior surgery (sensitivity = 91.6%) whereas CV identified the thrombus only in 7 pts (sensitivity = 73.3%). No false positive diagnosis of LVT was made by the two techniques (specificity = 100%). Six large and 4 small thrombi (1 false negative) were identified by 2D-Echo; 6 large and 1 small thrombi (4 false negative) were identified by CV. In conclusion, 2D-Echo showed a significantly higher sensitivity for LVT than CV in patients with prior Acute Myocardial infarction, especially for small thrombi.