Pulmonary arterial hypertension (PAH) is commonly associated with congenital heart disease (CHD) and relates to the type of the underlying defects and repair strategies. Large pulmonary shunts may develop PAH if untreated or repaired late. PAH, when present, markedly increases morbidity and mortality in CHD patients. Significant progress has been made for patients with Eisenmenger syndrome in pathophysiology, prognostication, and disease-targeting therapy. Patients with PAH-CHD and left-to-right shunting may benefit from late defect closure if pulmonary vascular resistance is normal or near normal. Patients with PAH-CHD and coincidental defects and also patients with previous repair of CHD should be managed as those with idiopathic PAH. All patients with PAH-CHD should be cared for at expert centres and those with Eisenmenger syndrome benefit from a proactive disease-targeting therapy approach. More research in this growing cardiovascular field is clearly warranted.