Firearm injuries are the second leading cause of death among US children. While injury prevention has been shown to be effective for blunt mechanisms of injury, the rising incidence of accidental gunshot wounds, school shootings, and interpersonal gun violence suggests otherwise for firearm-related injuries. The purpose of the study is to describe the incidence, injury severity, and institutional costs of pediatric gun-related injuries in Colorado. Pediatric patients (≤18 years), who sustained firearm injuries between 2008 and 2018, were identified from the trauma registries of three pediatric trauma centers in Colorado. Patients were stratified based on age: those younger than 14 years were defined as children and those 15 years to 18 years as adolescents. Our cohort (n = 308) was predominantly male (87%), with a median age of 14 years. The overall mortality rate was 11% (34/308), with significantly fewer children (5%) dying from their injuries when compared with adolescents (14%; p = 0.04). Sixty-five (21%) patients required blood product transfusions, with 23 (7.4%) patients receiving a massive transfusion. Overall, 52% (161/308) required a major operation, with 15% undergoing an exploratory laparotomy. One third (4/13) of the patients who had a thoracotomy in the emergency department survived to hospital discharge. Overall, 14.0% of patients had psychiatric follow-up at both 30 days and 1 year. The readmission rate for complications was 11.6% at 30 days and 14% at 1 year. The total cost of care for all pediatric firearm-related injuries was approximately US $26 million. The survivors of pediatric firearm injuries experience high operative and readmission rates, sustain long-term morbidities, and suffer from mental health sequelae. Combining these factors with the economic impact of these injuries highlights the immense burden of disease. This burden may be palliated by a multipronged approach, which includes the development and dissemination of injury prevention strategies and better follow-up care for these patients. Epidemiological, Level III.