The aim of this study was to assess the correspondence between two-dimensional echocardiographic (2D-Echo) and anatomic features of left ventricular thrombi (LVT), with particular reference to LVT shape and dimensions. The study population was composed of 23 patients who were admitted to our intensive cardiac care unit with an anterior acute myocardial infarction and who died during the hospitalization. Every patient underwent serial echocardiographic examinations, the last one performed within the 24 hours preceding death. The diagnosis of LVT required the agreement of three independent observers. Doubtful cases were considered as negative. With regard to shape, the LVT were defined as mural or protruding. Two measures of the LVT were obtained in each case: the longest dimension and the greatest one perpendicular to the initial dimension. At post-mortem examination we obtained sections of the heart comparable with an echocardiographic four chamber view. LVT were detected by 2D-Echo in 12/23 cases. Post-mortem examination confirmed the presence of LVT in these 12 patients. A thin apical thrombotic layer, whose presence had been defined previously as doubtful, was observed in another patient. The sensitivity of 2D-Echo was 92% and the specificity 100%. At 2D-Echo, shape was mural in 2 patients and protruding in 10. Complete agreement was found between 2D-Echo and anatomic findings as far as the morphology of LVT is concerned. The 2D-Echo measurements of LVT showed a high correlation with autopsy (r = 0.95; r = 0.86); we conclude that 2D-Echo provides accurate evaluations of the shape and the dimensions of LVT.