Chronic thromboembolic pulmonary hypertension (CTEPH) should be differentiated from other etiologies of pulmonary hypertension since surgical intervention may be potentially curative. The presentation of this illness is nonspecific and may mimic other cardiopulmonary disease states. Without treatment, progressive pulmonary hypertension, right heart failure, and death will ensue. Echocardiography, lung ventilation-perfusion scan, right heart catheterization, and angiography are required for proper diagnosis and preoperative assessment. Definitive treatment requires surgical resection of thromboembolic material. The role of medical therapy remains to be defined.