Advances in the management of congenital heart disease (CHD) in children have resulted in growing numbers of adults with CHD. Pulmonary arterial hypertension related to CHD (PAH-CHD) is a common complication, affecting up to 10% of patients; and can arise even after successful and complete defect repair, with severe and potentially fatal consequences. Careful work-up in these patients is essential, particularly hemodynamic assessment, and can help define the most appropriate therapeutic approach. Management can be challenging, but the therapeutic armamentarium is continually expanding and now includes surgical, transcatheter and medical options. Timely correction of defects along with early treatment with advanced medical therapies appears to improve quality of life and possible even improve survival. Interestingly most studies of PAH-CHD have focused on its most severely afflicted patients, those with Eisenmenger Syndrome, making it less certain how to manage PAH-CHD of milder degrees. This review summarizes our current understanding of PAH-CHD and emphasizes the need for close follow-up in specialized centers of care where close collaboration is common practice.