Primary pulmonary hypertension (PPH) is a condition characterized by sustained elevation of pulmonary artery pressure (PAP) without demonstrable cause. The most common symptom at presentation is dyspnea. Other complaints include fatigue, chest pain, syncope, leg edema, and palpitations. Right heart catheterization is diagnostic, showing a mean PAP >25 mmHg at rest and >30 mmHg during exercise, with a normal pulmonary capillary wedge pressure. In the National Institutes of Health-PPH registry, the median survival period was 2.8 years. Treatment is aimed at lowering PAP, increasing cardiac output, and decreasing in situ thrombosis. Vasodilators have been used with some success in the treatment of PPH. They include prostacyclin, calcium-channel blockers, nitric oxide and adenosine. Anticoagulation has also been advised for the prevention of deep vein thrombosis, pulmonary embolism, and in situ thromboses of the lungs. New drug treatments under investigation include L-arginine, plasma endothelin-I, and bosentan. Use of oxygen, digoxin, and diuretics for symptomatic relief have also been recommended. Patients with severe PPH refractory to medical management should be considered for surgery.