Primary pulmonary hypertension is a rare disease of unknown etiology, which mainly affects people in the third and fourth decades. Although the clinical cause is highly variable and spontaneous regression has been described, survival rates are usually poor, averaging only three years after diagnosis. Treatment with vasodilator agents, especially calcium channel blockers and prostaglandins, usually improves symptoms, but have not been shown to improve chances for survival. In a few selected patients who continue to deteriorate despite medical treatment, lung transplantation may be the only option for improving function and survival.