Background Previous studies have challenged the concept of contrast material-induced acute kidney injury (AKI) in adults; however, limited data exist for children and adolescents. Purpose To calculate the incidence and determine the risks of AKI in patients who received intravenous iodinated contrast media for CT. Materials and Methods This retrospective study was performed at a children's hospital from January 2008 to January 2018 and included patients aged 0-17 years in whom serum creatinine levels were measured within 48 hours before and after CT with or without contrast media. The incidence of AKI was measured according to the AKI Network guidelines. A subgroup analysis with propensity score matching of cases with control patients was performed. Differences before and after stratification based on estimated glomerular filtration rate (eGFR) were explored. Adjusted risk models were developed using log-binomial generalized estimating equations to estimate relative risk (RR). Results From a total of 54 000 CT scans, 19 377 scans from 10 407 patients (median age, 8.5 years; IQR, 3-14; 5869 boys, 4538 girls) were included in the analysis. Incidence rate of AKI for the entire sample was 1.5%; it was 1.4% (123 of 8844) in the group that underwent contrast-enhanced CT and 1.6% (171 of 10 533) in the group that did not (P = .18). In the contrast-enhanced CT group, AKI incidence was higher in the group with eGFR of at least 60 mL/min/1.73 m2 and in the group with eGFR lower than 60 mL/min/1.73 m2 (1.3% and 8.5%, respectively; P < .001) compared with the noncontrast group (0.1% and 2.7%, respectively; P < .001). Age was found to be a protective factor against AKI, with an RR of 0.96 (95% CI: 0.94, 0.99; P = .01), and contrast media increased risk in the subgroup analysis, with an RR of 2.19 (95% CI: 1.11, 4.35; P = .02). Conclusion The overall incidence of acute kidney injury after contrast-enhanced CT in children and adolescents was very low, and exposure to contrast media did not increase the risk consistently for acute kidney injury among different groups and analyses. © RSNA, 2022 See also the editorial by McDonald in this issue.