Chronic thromboembolic pulmonary hypertension (CTEPH) is uncommon. Its diagnosis should not be delayed as its prognosis is poor if not treated. In most cases, an acute pulmonary embolism is found in the medical history of the patient. Once suspected, a specific work-up should be performed in a pulmonary hypertension (PH) center. The ventilation/perfusion scan has a central role in this workup but the emergence of non invasive imaging technologies provides morphological and functional information which take part in the therapeutic decision making, such as operability. Surgical endarterectomy remains the only curative treatment. In some specific patients, percutaneous transluminal pulmonary angioplasty (AAP) is performed. This developing technique is a safe and efficient treatment on a clinical and hemodynamic standpoint. The main complication after AAP is lung reperfusion edema.