BACKGROUND: Computed tomography (CT) is useful for the diagnosis of local complications in children with acute pancreatitis but its role as a prognostic tool remains controversial. OBJECTIVE: To establish the correlation between the CT Severity Index and the Revised Atlanta Classification regarding unfavorable outcomes such as severe acute pancreatitis and need for Pediatric Special Care Unit attention in children with acute pancreatitis. MATERIALS AND METHODS: We conducted a retrospective and concordance cohort study in which we obtained abdominal CT scans from 30 patients ages 0 to 18 years with acute pancreatitis. Two pediatric radiologists interpreted the results using the CT Severity Index and the Revised Atlanta Classification. The kappa coefficient was determined for each scale. The association among severe acute pancreatitis, need for admission to the Pediatric Special Care Unit and CT systems were established using chi-square or Mann-Whitney U tests. The best CT Severity Index value to predict the need for admission to the Pediatric Special Care Unit was estimated through a receiver operating characteristic (ROC) curve. RESULTS: Mean CT Severity Index was 5.1±2.8 (mean ± standard deviation on a scale of 0 to 10) for the severe acute pancreatitis group vs. 3.8±2.7 for the mild acute pancreatitis group (P=0.230). The CT Severity Index for the children who were not hospitalized at the Pediatric Special Care Unit was 2.2±2.2 vs. 5.6±2.4 for the group hospitalized at the Pediatric Special Care Unit (P=0.001). Only parenchymal necrosis >30% was associated with severe acute pancreatitis (P=0.021). A CT Severity Index ≥3 has a sensitivity of 89% and specificity of 72% to predict need for admission to the Pediatric Special Care Unit. None of the Revised Atlanta Classification categories was associated with severe acute pancreatitis or admission to the Pediatric Special Care Unit. CONCLUSION: A CT Severity Index ≥3 in children with acute pancreatitis who require CT assessment based on clinical criteria is associated with the need for admission to the Pediatric Special Care Unit. We found that pancreatic necrosis greater than 30% is the only tomographic parameter related to severe acute pancreatitis. New studies with a greater sample size are necessary to confirm this result.