Primary pulmonary hypertension and cor pulmonale represent forms of precapillary pulmonary hypertension due to intrinsic lung disease. In the case of primary pulmonary hypertension, this is due to disease of the pulmonary vasculature while cor pulmonale is related to diseases of the pulmonary vasculature, airways, or interstitium. Patients present with signs and symptoms of right ventricular dysfunction and low cardiac output including dyspnea, chest pain and peripheral edema. Therapy is directed at the underlying disease and may include supplemental oxygen for diseases causing chronic hypoxemia and anticoagulation for thrombotic disease. Vasodilator therapy has variable efficacy for pulmonary vascular disorders. Postacyclin by continuous infusion has been a major advance in the therapy of primary pulmonary hypertension and has prolonged survival and delayed the need for lung transplantation. Bosentan, an endothelin receptor blocking agent is the first oral medication approved for the therapy of pulmonary hypertension.