Over the past 40 years, significant advances have been made in the diagnosis and management of congenital heart defects. Improvements in diagnostic and interventional cardiology, surgical technique, cardiopulmonary bypass and post-operative intensive care have all contributed to a reduction in mortality and morbidity. Despite these advances, pulmonary hypertension caused by congenital heart defects remains a significant problem in the immediate post-operative period, as well as long term. This article reviews the pathophysiology of pulmonary hypertension due to congenital heart disease and discusses the options available for the management of this condition.