Primary pulmonary hypertension (PPH) is a pulmonary vascular disease characterized by an elevation in mean pulmonary artery pressure and pulmonary vascular resistance. Recently, PPH gained national attention because of its association with appetite suppressants. PPH may also be associated with pregnancy, hypothyroidism, autoimmune disorders, human immunodeficiency virus infection, and the use of drugs such as oral contraceptives and cocaine. Patients with PPH may report dyspnea on exertion and fatigue. Early diagnosis is crucial. New therapeutic regimens have dramatically reduced morality rates and improved quality of life by halting the progression of pulmonary vascular remodeling and averting right-sided heart failure. These therapies include high-dose calcium channel antagonists, anticoagulants, and continuous intravenous prostacyclin. Lung or heart-lung transplantation remains a vlable therapeutic option for patients who are treated late in the disease process, who are not responsive to medical management, or who remain symptomatic and continue to deteriorate.