Interrupted aortic arch (IAA) is defined as complete luminal and anatomic discontinuity between the ascending and descending aorta. Because almost all patients with IAA become critically ill during the neonatal period, they should undergo urgent corrective surgery. This clinical urgency necessitates a fast and accurate noninvasive diagnostic method. Although echocardiography remains the primary imaging tool for this purpose, it is not always sufficient for planning surgical correction of IAA, principally due to a limited acoustic window and the inexperience of imagers. In this context, multislice CT angiography is regarded as an appropriate imaging technique complementary to echocardiography because it is fast, accurate, and objective for the diagnosis of IAA. In this article we describe what cardiac radiologists should know about IAA in their clinical practice, including clinicopathological features, CT features with contemporary surgical methods and postoperative complications, and differentiation from coarctation of the aorta and aortic arch atresia.