Pulmonary embolism is a frequent and serious complication in surgical patients in hospital. Rapid and accurate diagnosis is essential to allow treatment appropriate to its severity without delay. As clinical signs and symptoms are noncharacteristic, rapidly performed, noninvasive procedures should first be carried out, such as echocardiography and spiral computer tomography, to verify the diagnosis. Among laboratory methods, the D-dimer test is the only one that has major value in supporting or excluding a thrombotic/thromboembolic event. If findings remain equivocal ventilation-perfusion scintigraphy and pulmonary angiography are justified, but these are now regarded as second-line diagnostic procedures in acute embolism because of logistic problems (availability, transport of unstable patients). Since acute pulmonary embolism is frequently a complication of deep vein thrombosis in the leg, however, prophylaxis of venous thrombosis remains particularly important.