Pediatric patients with complex congenital heart disease (CHD) face a lifetime of treatment with interventional therapeutic and palliative procedures. Echocardiography remains the mainstay for noninvasive imaging of congenital heart lesions. This often is supplemented with diagnostic cardiac catheterization for additional anatomic and physiologic characterization. However, recent technological improvements in computed tomography (CT) and magnetic resonance imaging (MRI) have led to an increased focus on the use of these techniques given their better safety profile. This study aimed to review the authors’ experience with a 320-slice multidetector CT scanner in the evaluation of CHD in children. This retrospective case study investigated 22 infants and young children with a provisional diagnosis of CHD. Their anatomic evaluation was performed using a 320-slice Aquilon ONE CT scanner. Of these 22 patients, 14 were examined without cardiac gating. This was subsequently modified to a prospective gated, targeted protocol to decrease the radiation dose. The images were interpreted by an experienced radiologist and a pediatric cardiologist. Continuous variables were expressed as mean and standard deviation or range, and the two imaging protocols were compared. A comparison of exposure rates with those from other pediatric studies that had used the 64-slice CT angiography also was performed. For the first group of patients, with nongated CT examinations, the mean effective whole-body radiation dose was 1.8 ± 0.71 millisieverts (mSv) (range, 0.96–3.2 mSv). For the second group, the mean was 0.8 ± 0.39 mSv (range, 0.4–1.5 mSv). Although the radiation dose was reduced dramatically, clinicians must be vigilant about the cumulative risk of radiation exposure.