Pulmonary embolism is the third most common acute cause of death in the United States. There are approximately 500,000 cases annually in this country, leading to death in 50,000. Subjective symptoms and objective findings can oftentimes be confusing and nonspecific.Apulmonary embolismis defined as an occlusion of one or more pulmonary vessels by material that has traveled there from outside of the lung and is usually caused by a dislodged thrombus that originated in the deep veins of the legs or pelvis. Risk factors include older age, prior thromboembolism, immobility, cancer, chronic disease, congestive heart failure, pelvic and lower extremity surgery, varicosities, obesity, and oral contraception.This article will discuss current modalities that are used in the evaluation of deep venous thromboembolism and pulmonary embolism and include ventilation/perfusion scan, ultrasonography, impedance plethysmography, pulmonary anglography, and newer tests including D-dimer assays and spiral computed tomography. Medical management including simple and complex decision making, anticoagulation, and thrombolytic therapy will also be discussed.An ounce ofpreventionis worth a pound of gold—identification of risk factors and the use of appropriate therapeutic measures can reduce an individual's risk for deep venous thromboembolism and pulmonary embolism.