Congenital heart disease affects up to 1% of the population 1 and is more common in females in both children and adults. With improving diagnostics and therapeutics, there is an increasing population of adults with congenital heart disease. This is because of both improved survival of children with congenital heart disease, 95% of whom reach adulthood, and new diagnoses of milder forms of congenital heartdiseaseinadults.Intheyear2000,thenumberofadults and children with congenital heart disease was nearly equal. 1,2 Congenital heart disease is increasingly being recognizedasagroupoflesionsofmultifactorialetiologywithboth genetic and noninherited factors playing a role in their development. 3-5 For adults of reproductive age, the presence of congenital heart disease has genetic implications regarding risk to future children and, for women, the additional risks related to pregnancy. Depending on their size and location, simple shunt lesions may remain asymptomatic during childhood and be initially diagnosed in adulthood. Not infrequently, new symptoms develop in adults as comorbidities, such as hypertension or lung disease, unmask the previously silent shunt physiology. Another common scenario is an adult imaged for an unrelatedindicationinwhomaserendipitousdiagnosisofashunt is made. Therefore, it is imperative that radiologists be familiarwiththeimagingfindingsofvariousshuntsaswellastheir clinical implications. In this article, we will review the radiographic imaging of simple shunts in adults, including typical chest radiographic findings and the roles of computed tomography (CT) and magnetic resonance (MR) in diagnosis and in guiding treatment. We will also address the relevant anatomy and physiology, diagnostic findings, and therapeutic options for adults with simple shunts, initially providing an overview. We will thenfurtherdetailthefeaturesuniquetospecificlesions,including atrial septal defect (ASD), patent foramen ovale (PFO), partial anomalous pulmonary venous return (PAPVR), ventricular septal defect (VSD), and patent ductus arteriosus (PDA).