Background: The diagnosis of pulmonary embolism (PE) remains difficult. Ultrasounds allow for the exploration of the venous system to great extent and for the detection of indirect signs of PE. The aim of this study was to determine the incidence of acute cor pulmonale (ACP) and deep venous thrombosis (DVT) found by ultrasonographic techniques in a population of patients with PE. Methods: One hundred and seventy-three consecutive patients with acute PE (diagnosed either by spiral computed tomography or selective pulmonary angiography) had subsequently both transthoracic echocardiography (TTE) and venous ultrasonography. The diagnostic criterion used for defining ACP by echocardiography was the right to left ventricular end-diastolic area ratio over (or equal to) 0.6 with paradoxical septal wall motion. The diagnosis of DVT rested on vein incompressibility. Results: ACP was found in 56% of our patients while 75% were found to have DVT and 89% of the patients had either ACP or DVT or both. All of the patients with proximal PE had ACP and/or DVT. The presence of ACP using echocardiography was significantly different according to the localization of PE ( P<0.0001) and the clinical presentation ( P=0.0001). The incidence of ACP and/or DVT was significantly different according to the localization of PE ( P=0.001). Echocardiography combined with venous ultrasonography had improved the diagnosis value of venous ultrasonography in only 4% of patients with distal PE ( P=0.65). Conclusion: A combined strategy using echocardiography with venous ultrasonography improves significantly the diagnostic value of venous ultrasonography in proximal and lobar PE and fails in distal PE.