The patient presenting to the emergency department with signs and symptoms suggestive of pulmonary embolism often represents a diagnostic challenge. Many conditions may mimic the signs and symptoms of acute pulmonary embolism. A combination of studies to evaluate both the pulmonary vascular bed (ventilation perfusion scan and pulmonary angiogram) and the deep venous system of the lower extremities (impedance plethysmography, Doppler ultrasound, and venography) can be used to evaluate a patient with suspected pulmonary embolism. Once the diagnosis has been confirmed, secondary preventive therapy (unfractionated heparin and inferior vena cava interruption) or primary therapy (thrombolytic agents and embolectomy) can be instituted. Newer management strategies for the diagnosis and treatment for pulmonary embolism are on the horizon.