ObjectivesHemorrhage is a common complication of trauma. We evaluated age and sex differences in treatment with blood product transfusions and massive transfusions as well as in-hospital mortality following trauma at a Level 1 Trauma Center. MethodsThis cross-sectional study evaluated trauma data from a Level 1 trauma center registry from January 2013 to December 2017. The primary outcome was amount of blood products (packed red blood cells (PRBCs), plasma, platelets), and massive transfusion (MT) by biological sex and by age group: 16-24 (youth), 25-59 (middle age), and >=60 (older age) The secondary outcome was in-hospital mortality to hospital discharge. ResultsThere were 13596 trauma patients in the registry, mean age was 48 years, 4589 (34%) female and 9007 (66%) male, and median ISS of 9. Male patients received significantly more PRBC transfusions than female patients within 4-hours 6.6% vs 4.4%, and 24-hours 6.7% vs 4.5% respectively. Older patients received significantly fewer PRBC transfusions within 4-hours and 24-hours than their younger counterparts, with 6.9% in the youth group, 6.8% in the middle age group, and 3.9% in the older group (p<0.001). When adjusted for injury severity, the odds of receiving a blood transfusion within 4 hours of injury was significantly lower in older females. Using multivariate analysis, predictors of mortality included (in order of significance) injury severity, older age, transfusion within 4 hours of injury, penetrating trauma, and male sex. ConclusionIn this large trauma cohort, older female trauma patients were less likely to receive blood products compared to younger females and to their older male counterparts, even after adjusting for injury severity. Predictors of mortality included injury severity, older age, early transfusion, penetrating trauma, and male sex. Following trauma, older women appear vulnerable to undertreatment. Further study is needed to determine the reasons for these differences and their impact on patient outcomes.