The development of multi-slice spiral computed tomography (CT) has increased the clinical use of cardiac CT imaging in patients with congenital heart disease. Multi-slice CT has the advantages of fast scan speed; high spatial resolution, enabling the acquisition of isotropic volume data; and simultaneous evaluation of airways and lung parenchyma, thus increasing the ability to answer most clinical questions about structural abnormalities in patients with congenital heart disease. When coupled with electrocardiography-gating, multi-slice spiral CT can be used in functional evaluations, including ventricular wall motion, ventricular ejection fraction, and motion of cardiac valves, as well as enabling the performance of high-quality coronary CT angiography. In this article, we review imaging techniques of multi-slice spiral CT and imaging findings in pediatric and adult patients with various congenital heart diseases.