Objectives: We asked whether age or injury severity drives blood use patterns in paediatric trauma.Background: Transfusion for paediatric trauma care is complicated by known developmental differences in coagulation and injury patterns.Methods/Materials: We linked 10 years of Trauma Registry and blood bank data, 2011-2020, for all acute trauma patients aged <18 treated at a large US Level 1 adult and paediatric trauma centre. We assessed age, injury severity and mechanism for association with any blood use, use within the first 4 h of care, and resuscitation balance, using grouped-age Chi-square and multivariable regression models.Results: Of 60 066 acute trauma arrivals at our centre in the study period, 7979 (13.3%) met inclusion criteria. Median age (IQR) was (7.6[2.4-14.5]); 6230(78.1%) were < 15years old; 590(7.4%) received any blood products; and 128(1.6%) died. Among the 5842 (73.2%) patients with impact-related injury, 2023(34.6%) met standards for severe injury (New Injury Severity Score [NISS] ≥ 16); 541(9.3%) were transfused, 171(31.6%) in the first 4 h and 72(13.3%) using ≥3 units of products in the first hour. Firearms injuries were the most severe, most likely to be transfused urgently, using balanced resuscitation, and to die (p < 0.001 for all). Multivariable logistic regression showed any blood use as strongly associated with NISS (Odds Ratio 1.124832; p < 0.0001; 95% CI 1.11-1.13) but not with age (OR 0.98; p = 0.07; 95% CI 0.96-1.00). Conclusion:Transfusion in the care of acute paediatric trauma is uncommon (<10% of injured minors in our cohorts received any blood products), and injury severity, particularly firearms injury-not age-drove transfusion.