Advances in imaging with faster scans and routine use of thin-section images have allowed for the regular detection of congenital heart disease (CHD) in adults. Simultaneously, surgical and medical treatments have allowed children with complex CHD to live well into adulthood. The net effect is that more adults are alive with CHD than children. CHD is truly an adult condition! This chapter will cover the more common anomalies initially detected in adults including septal defects, bicuspid aortic valve, anomalous pulmonary venous return, Ebsteins anomaly, and coronary anomalies, which may also go undetected until adulthood. The chapter will cover common associations with these conditions. Tetralogy of Fallot (TOF) is the most common surgically corrected congenital heart disease seen in adults. Right ventricle end-diastolic volume normalized to body surface area helps to drive the need for intervention. Surgical correction for transposition of the great arteries previously consisted of inflow switching but now consists of an arterial switch procedure. With repaired complex congenital heart disease, two phases of imaging for CT angiography are strongly considered. This can help overcome flow artifacts that may be seen with a single phase in this complex anatomy.