Patients with pulmonary artery blood pressures that are chronically elevated to levels of the order of the systemic blood pressures, form a distinct clinicopathologic entity. This condition may complicate a ventricular septal defect, Eisenmenger's complex, patent ductus arteriosus, atrial septal defect, and mitral stenosis, and it may occur as idiopathic pulmonary hypertension. The clinical picture is dominated by symptoms and signs characteristic of pulmonary hypertension, which often mask underlying cardiac anomalies, and definitive pathologic changes occur in the pulmonary vasculature. The term hypertensive pulmonary vascular disease is therefore suggested for this distinct group of patients.