The reported incidence of anomalous coronary arteries among children is 0.17%, but it is much greater (8%) among children with tetralogy of Fallot (TOF). The diagnosis of coronary artery anomalies can be difficult using invasive aortography and is not without risk. Technical improvements with multidetector computed tomography (MDCT), including a reduced effective radiation dose, make cardiac CT angiography an attractive alternative not only because the risks of an invasive examination are avoided, but also because sedation risks also are eliminated in most cases. This report highlights 256-slice MDCT imaging of the coronary arteries in a nonsedated 26-day-old infant using an effective radiation dose of only 0.51 millisieverts (mSV).