In recent years, there has been a major advance in the treatment of pulmonary hypertension. New medications are continually added to the therapeutic arsenal. The prostanoids are among the first agents used to treat pulmonary hypertension and are currently considered the most effective. This case study describes a 63-year-old man who was diagnosed with chronic thromboembolic pulmonary hypertension and successfully treated with subcutaneously administered treprostenil for 6 months before a successful pulmonary thromboendarterectomy. Treatment of chronic thromboembolic pulmonary hypertension often requires a multidisciplinary approach before surgery. Further evaluation of prostanoids is needed to define their role and time of initiation of medical therapy in these patients.