Chronic thromboembolic pulmonary hypertension (CTEPH) is the presence of mean pulmonary artery pressure (mPAP) ≥ 25 mmHg following an episode of pulmonary thromboembolism (PTE). At present, PH is classified into five groups based on similarities in pathophysiology and clinical management. CTEPH belongs to WHO PH group 4, and is a rare medical condition that is severely underdiagnosed and associated with significant rates of mortality and morbidity. This slide set covers the epidemiology, pathogenesis, and treatment of CTEPH.