Acute pulmonary embolism has a wide prognostic spectrum, ranging from sudden death within minutes of a thromboembolic episode to a benign treatable condition associated with a stable clinical course and no long-term sequelae. In patients who survive an initial thromboembolic episode and receive antithrombotic therapy, the clinical course can be complicated by recurrent nonfatal venous thromboembolism, fatal pulmonary embolism, the postthrombotic syndrome, and chronic thromboembolic pulmonary hypertension. Identifying which patients are at increased risk of experiencing these sequelae is important in decision making relating to the aggressiveness of initial antithrombotic therapy, the duration of antithrombotic therapy, and the frequency of clinical surveillance. In addition, this information may be helpful to clinicians in discussing disease prognosis with patients. The objectives of this review are to provide reasonable estimates of the risks of recurrent nonfatal venous thromboembolism, fatal pulmonary embolism, the postthrombotic syndrome, and chronic thromboembolic pulmonary hypertension in patients with treated pulmonary embolism, and to identify risk factors for these sequelae.