Pulmonary arterial hypertension of variable degree is commonly associated with adult congenital heart disease. Depending on size and location of the underlying cardiac defect as well as on repair status, pulmonary arterial hypertension may present with or without reversed shunting and associated cyanosis (ie, Eisenmenger syndrome). We review available data on etiology, clinical presentation, prognosis, and management strategies of pulmonary arterial hypertension in adult patients with congenital heart disease. In addition, we discuss the numerous complications associated with Eisenmenger syndrome, representing a multisystem disorder. Finally, we present general management strategies and emerging disease-targeting therapies.