Pulmonary arterial hypertension is a group of disorders defined by a progressive elevation of pulmonary vascular resistance in the small pulmonary arteries and arterioles. In its untreated form, the disease causes progressive dyspnea and severe activity limitation resulting in premature death due to right ventricular failure. However, the advent of multiple-targeted medical therapies has significantly altered the prognosis of this disorder, allowing patients to live longer with increased functional ability. Given the trend in prognosis and functionality, this review revisits the possible role for exercise training in patients with pulmonary arterial hypertension. The evidence suggesting that exercise may be safe in these patients is summarized and a potential exercise prescription is suggested.