Primary Lung Hypertension is a serious disease of unknown cause. Various genetic, vasoconstriction, proliferation and procoagulation factor participate in etiology and pathogenesis. In establishing the diagnosis it is necessary to exclude secondary, particularly embolic cause of pulmonary hypertension. There are diseases with associated primary pulmonary hypertension. Present therapy improves symptoms of the disease, three years after the diagnosis is established, 75% of patients survive. In the therapy of primary pulmonary hypertension, the recommended drugs are calcium channel blockers, epoprostenol, oxygen therapy and anticoagulant drugs. The new, clinically tested drugs include inhalation and oral analogs of prostacyclins, endothelin receptor antagonists and phosphodiesterase blockers.