Pulmonary arterial hypertension is a progressive and incurable disease. Over the past two decades, significant advances have been made in understanding and thus managing this disease. Multiple therapeutic options are currently available and optimizing the treatment of pulmonary arterial hypertension has become complex. Patients who meet the American College of Chest Physicians criteria for vasoresponsiveness can be safely and effectively treated with high-dose calcium channel blockers but require close follow up to assure durability of response. Patients with World Health Organization (WHO) functional class IV status and those with determinants of high risk for progression and death should be treated with an infused prostanoid agent without delay. These patients should also be referred early after stabilization for transplant evaluation. Patients with WHO functional class II status benefit from early initiation of oral therapies. Those with WHO functional class III status and lower determinants of risk for progression may receive treatment with one or more oral or inhaled agents, though many experts would advise early use of infused prostanoids for these patients as well.