BackgroundRoad traffic injuries are a major cause of mortality and disability among children and adolescents, particularly among individuals aged 5–25 years. According to the 2021 Road Traffic Accident Statistics Report, adolescents aged 15–19 years accounted for the highest proportion of injuries and fatalities, representing 22.0% of all cases. Early identification of factors associated with mortality may facilitate risk assessment and improve the management of injured patients.ObjectiveObjective to identify factors associated with 24-hour mortality among children and adolescents with road traffic injuries who presented to the Emergency Department of Khon Kaen Hospital.MethodsA retrospective case-control study was conducted among patients aged 0–19 years who sustained road traffic injuries and were treated at the Emergency Department of Khon Kaen Hospital between January 2014 and December 2021. Patients triaged as Level 1 (resuscitation level) were included. The study population comprised two groups: patients who died within 24 hours of presentation (n = 144) and patients who survived beyond 24 hours (n = 144).ResultsA total of 288 critically injured patients were enrolled. Of these, 144 patients died within 24 hours and 144 survived. Most deceased patients were male (n = 115, 79.9%), and the age group with the highest number of deaths was 15–19 years (n = 104, 72.2%). After adjustment for potential confounders, factors significantly associated with 24-hour mortality were initial hypotension on arrival at the emergency department (AOR 182.11; 95% CI 20.00–1657.48; p < 0.001), thoracic injury (AOR 4.94; 95% CI 1.87–13.05; p = 0.001), an initial Glasgow Coma Scale (GCS) score of 3–8 (AOR 96.08; 95% CI 4.48– 2057.49; p = 0.003), and an Abbreviated Injury Scale (AIS) score greater than 3 (AOR 3.26; 95% CI 1.11–9.57; p = 0.031).ConclusionInitial hypotension, thoracic injury, an initial Glasgow Coma Scale score of 3–8, and an Abbreviated Injury Scale score greater than 3 were significantly associated with 24-hour mortality among children and adolescents with road traffic injuries. These factors may be useful for early risk assessment and monitoring of severely injured patients in the emergency department. Further studies are required to validate these findings and evaluate their applicability in clinical practice.