BACKGROUND: Limited data are available describing paediatric pulmonary arterial hypertension. AIMS: To characterize the epidemiology, management and impact on quality of life and outcome of paediatric pulmonary arterial hypertension, excluding persistent pulmonary hypertension of the newborn and pulmonary arterial hypertension caused by congenital heart disease. METHODS: In this multicentre study, children with pulmonary arterial hypertension were included and followed prospectively for two years at 21 referral centres in France. WHO functional class, 6-minute walk distance and quality of life (CHQ-PF50 questionnaire) were evaluated. RESULTS: Fifty children were included with a mean age of 8.9 +/- 5.4 years from May 2005 until June 2006. The estimated prevalence for pulmonary arterial hypertension was 3.7 cases/million. Patients had idiopathic pulmonary arterial hypertension (60%), familial pulmonary arterial hypertension (10%), pulmonary arterial hypertension associated with, but not caused by, congenital heart disease (24%), pulmonary arterial hypertension associated with connective tissue disease (4%) or portal hypertension (2%). During follow-up, the combination of pulmonary arterial hypertension-specific therapies was increasingly prescribed (44% patients versus 22% at inclusion). Patients remained stable regarding clinical status, 6-minute walk distance and quality of life. Survival estimates after one and two years were 86% (95% CI 76, 96) and 82% (95% CI 71, 93), respectively. CONCLUSIONS: In children, idiopathic/familial pulmonary arterial hypertension accounts for the majority of cases. A specific pulmonary arterial hypertension group in conjunction with congenital heart disease can be identified that resembles patients with idiopathic pulmonary arterial hypertension. Combined pulmonary arterial hypertension-specific therapies may have contributed to disease stability and favourable survival.