Emergency two-dimensional echocardiography was carried out in 61 patients admitted to an intensive care unit for suspected pulmonary embolism, in order to find out whether signs of acute cor pulmonale (ACP) were present or absent. Pulmonary angiography was subsequently performed to confirm or infirm the diagnosis of pulmonary embolism. Only 7 out of 13 patients with normal echocardiography had no pulmonary embolism. All other patients who showed echocardiographic signs of ACP had pulmonary embolism. Thus, the finding of normal echocardiographic results does not necessarily exclude a diagnosis of pulmonary embolism. Conversely, the presence of echocardiographic signs of ACP in a suggestive context provides a near-certain diagnosis of pulmonary embolism.