Pulmonary arterial hypertension (PAH) is a rare condition characterised by increased pulmonary vascular resistance leading to right heart failure and death. The clinical classification distinguishes idiopathic PAH, familial PAH, and PAH associated with other conditions (connective tissue disease, congenital heart disease, portal hypertension, human immunodeficiency virus infection, or appetite suppressant exposure). Echocardiography is the initial investigation of choice for non-invasive detection of PAH but measurement of pulmonary pressures and cardiac output during right heart catheterization is mandatory to confirm the diagnosis. Conventional therapy includes non-specific drugs (warfarin, diuretics). Intravenous epoprostenol is the first line treatment for the most severe patients. In the other situations, the first-line therapy may include bosentan, sildenafil, or a prostacyclin analogue. Recent advances in the management of PAH have markedly improved prognosis. The evolution of therapy from vasodilators to antiproliferative agents reflects the advancement in our understanding of the mechanisms mediating pulmonary arterial hypertension.