Pulmonary arterial hypertension (PAH) can cause morbidity and mortality in children. Although adult and pediatric PAH share many similarities, many differences have been found in children. Thus, a new classification for pediatric pulmonary hypertensive vascular disease has been proposed. Both child and adult gene mutation carriers with PAH tend to have worse prognoses. Pediatric patients present with better preserved functional class, and parents should pay high attention to any children with unexplained shortness of breath, fatigue or syncope, as symptoms of PAH in children are often misleading. Right heart catheterization is necessary for diagnosis. Although there are few medications approved for pediatric PAH and evidence-based treatment algorithms for children are still lacking, the survival of pediatric patients has been improved significantly since targeted therapies approved for adults were introduced to pediatric patients. PAH in children is unique, and further studies are needed to have a better understanding of it.