Chronic thromboembolic pulmonary hypertension (CTEPH) is a distinct pulmonary vascular disease caused by chronic obstruction of major pulmonary arteries that is amenable to cure by pulmonary endarterectomy (PEA). Main features of CTEPH as opposed to pulmonary arterial hypertension (PAH) are a nonhomogeneous distribution of disease in segments of the pulmonary vascular tree and its association with venous thromboembolism (VTE). Although the exact prevalence and annual incidence of CTEPH are unknown, recent data from the United Kingdom suggest that this condition may occur in ≈5 individuals per million per year,1 making CTEPH one of the most common subsets of precapillary pulmonary hypertension (PH). Still, CTEPH remains an orphan disease. Given that CTEPH is potentially curable by a complete PEA, the authors surveyed all major centers in Europe and the United States, and the results confirm prior concerns regarding adequate diagnosis and treatment of CTEPH. There are currently 1.7 PEAs per million of population performed in Europe annually compared with 0.9 in the United States. Although these numbers represent a steady increase over the last several years, they underscore the underdiagnosis of the disease, as well as a common delay or lack of referral to expert centers for surgery. Education of physicians to identify CTEPH as a potential diagnosis and training of PEA surgeons to master the techniques of a complex and challenging operation must be supported by worldwide educational activities. Since the last comprehensive review on CTEPH in Circulation in 2006,2 several milestones in CTEPH research and management have been reached. Those have been set by (1) the International CTEPH Association, which was founded in 2006 as “Association for Research in CTEPH” with the goal to increase awareness, foster worldwide collaboration among centers, provide a platform for surgical centers, establish the European and International CTEPH registries, facilitate training of …