Pulmonary endarterectomy is the treatment of choice for many patients with chronic thromboembolic pulmonary hypertension. Although potentially curative, some patients receive no benefit and have poor outcomes. This review will look at the new research in the pathophysiology of the disease and developments in perioperative care, which may help to understand the difference in outcomes.Chronic thromboembolic pulmonary hypertension is an under-recognized condition, affecting more patients than previously thought. Molecular research focused on the mechanisms of pulmonary hypertension may help to explain differing patient outcomes after surgery.Pulmonary endarterectomy is a successful treatment of chronic thromboembolic pulmonary hypertension. Better understanding of the underlying pathophysiology will help in patient selection for surgical intervention.