The BIG score (base deficit + [2.5 × international normalized ratio] + [15 - Glasgow Coma Score]) was compared with the Pediatric Trauma Score (PTS) for predicting mortality in pediatric patients with multiple trauma. This retrospective, single-center study included 318 consecutive pediatric patients (aged 1-18 years) with multiple trauma who were admitted to the emergency department between January 1, 2021, and December 31, 2023. The demographic characteristics, clinical characteristics, and trauma scores (BIG score and PTS) were compared between survivors and nonsurvivors to identify factors associated with mortality. A PTS of 7 had 100% sensitivity and 81.03% specificity for predicting mortality, with an area under the curve of 0.97 (95% confidence interval 0.9-0.99). Although the positive predictive value (PPV) was low (33.7%), the negative predictive value (NPV) was 100%. A BIG score of 13.7 was identified as the cutoff for mortality, with 92.86% sensitivity and 95.52% specificity (area under the curve 0.98, 95% confidence interval 0.96-0.99). The PPV was 66.7% and the NPV was 99.3%. Both the PTS and the BIG score were strong predictors of mortality in pediatric patients with multiple trauma. The BIG score had a higher specificity and PPV, whereas a PTS of 7 had 100% sensitivity and a higher NPV.