To determine the incidence, characteristics, and factors associated with mortality after major traumatic injury in adolescent and young people in the Australian Capital Territory (ACT). A combined retrospective analysis of the National Coroners Information System and ACT Level 1 Trauma Centre registry data from July 2007 to June 2012 was conducted. Inclusion criteria were age 16 to 24 years, injury occurring within the ACT or surrounding region of responsibility, Injury Severity Score of more than 15, intensive care unit admission, hospital stay of more than 3 days, penetrating injury, or death. There were 714 adolescent and young adults recorded in the TCH trauma registry and National Coroners Information System. Injury rates remained consistent over the 5-year study period. Over half the injuries occurred in the districts surrounding the ACT. The largest subset represented was 18 to 21 years (47.8%). Road trauma was the most prevalent injury mechanism overall (58.4%), reaching statistical significance within the 18- to 21-year subset (39.9%). Other dominant injury mechanisms overall were recreation (15.4%) and violence (15.3%); self-inflicted violence constituted 45.8% within the larger violence group. Variables associated with mortality included those injured within the ACT (odds ratio [OR], 0.4; 95% confidence interval [CI], 0.23-0.76) and the injury categories of severe (OR, 52.27; 95% CI, 24.71-110.58) and critically injured (OR, 770.73; 95% CI, 267.37-2221.73). The largest demographic affected by major trauma in the ACT and surrounds is young people aged 16 to 24 years. The focus of injury prevention may benefit from targeting young people involved in multiple risk behaviors that contribute to road trauma, interpersonal and self-inflicted violence, as well as high-risk recreation activities. Further research examining the complexity and relationship between these risk factors is required, as well as the long-term burden associated with caring for injured patients in this age group.