For physicians to admit that a group of patients remains for whom no cure is available in modern medicine is intellectually unsatisfying. Pulmonary arterial hypertension is a rare condition. Because the symptoms are nonspecific and the physical finding can be subtle, the disease is often diagnosed in its later stages. The natural history of pulmonary arterial hypertension is usually progressive and fatal. At the 1998 Primary Pulmonary Hypertension World Symposium, clinical scientists from around the world gathered to review and discuss the future of pulmonary arterial hypertension. Bringing together experts from a variety of disciplines provided the opportunity for a better understanding of the pathology, pathobiology, risk factors, genetics, diagnosis and treatment for pulmonary arterial hypertension. Remarkable progress has been made in the field of pulmonary arterial hypertension over the past several decades. The pathology is now better defined and significant advances have occurred in understanding the pathobiological mechanisms. Risk factors have been identified and the genetics have been characterised. Advances in technology allow earlier diagnosis as well as better assessment of disease severity. Therapeutic modalities such as new drugs, e.g. epoprostenol, treprostinil and bosentan, and surgical interventions, e.g. transplantation and blade septostomy, which were unavailable several decades ago, have had a significant impact on prognosis and outcome. Thus, despite the inability to really cure pulmonary arterial hypertension, therapeutic advances over the past two decades have resulted in significant improvements in the outcome for children with various forms of pulmonary arterial hypertension. This review of pulmonary arterial hypertension will highlight the key features of pulmonary hypertension in infants and children and the current understanding of pulmonary arterial hypertension with specific recommendations for current practice and future directions.