Intracardiac shunts are among the most common cardiac lesions seen in adult patients with congenital heart disease. Shunt lesions comprise much of the de novo congenital heart disease diagnosed in adults and engender a wide range of pathophysiologic consequences with a variety of treatment options. This article discusses the pathophysiology, clinical presentation, indications for intervention, late management issues, and pregnancy in adults with atrial septal defects, ventricular septal defects, and patent ductus arteriosus.