Pulmonary arterial hypertension (PAH) develops from an abnormal interaction between the endothelium and smooth muscle cells in the pulmonary vasculature and is characterized by a progressive rise in pulmonary vascular resistance resulting from vascular remodeling, vasoconstriction, and cellular proliferation. Three classes of drugs have been approved for the treatment of PAH that are based on results from small, short-term clinical trials: prostacyclin analogues, endothelin-receptor antagonists, and phosphodiesterase type 5 inhibitors. The pharmacologic management of PAH is rapidly evolving, as newer therapeutic targets that stabilize or reverse pulmonary vascular disease and target right ventricular function are being sought and as clinical practice patterns shift in favor of earlier diagnosis and aggressive treatment. This article reviews the current evidence for approved PAH treatments, alluding to the strengths and weaknesses of available trial data, briefly discusses combination therapy, and highlights the practical management aspects of approved drug therapy.