Pulmonary arterial hypertension (PAH) is a disease that leads to characteristic vascular wall remodeling and hemodynamic alterations. Consequently, this pulmonary vascular disease contributes to substantial morbidity and mortality in afflicted patients. PAH may be idiopathic in nature or associated with connective tissue disease, chronic liver disease, human immunodeficiency virus, congenital heart disease, and a growing list of other conditions. There are currently nine Food and Drug Administration-approved therapies for specific PAH treatment. Therapeutic targets include prostacyclin replacement, endothelin-1 antagonism, and phosphodiesterase-5 inhibition. This article focuses on the prostanoid treprostinil and explores its role in the management of patients with PAH.