This chapter discusses the current investigation and management of pulmonary thromboembolic disease, including the role of the Wells’ score for predicting likelihood of deep venous thrombosis and pulmonary embolism. Questions about the value of D-dimers and inferior vena caval filters, how long to continue anticoagulation, and how to predict risk from PE to determine who can be managed early as an outpatient (the PESI score) are answered. The acute management of massive pulmonary embolism is highlighted, including the role of thrombolysis and surgery. Thromboembolic disease in pregnancy is discussed, along with issues relating to the oral contraceptive pill and flight prophylaxis. Air, fat, amniotic fluid, and rarer sources of emboli are also covered.