Background: To determine the incidence and characteristics of major traumatic injury treated in the Australian Capital Territory (ACT) over a 5-year period. Methods: A retrospective analysis of ACT Level 1 Trauma Centre registry data from July 2007 to June 2012 was conducted. Inclusion criteria were: major trauma (Injury Severity Score (ISS) >15), intensive care unit admission, hospital stay >3 days or penetrating injury. Results: There were 931 patients with an ISS >15, a 12.5% increase over the 5-year period (P = 0.003). Unadjusted mortality rates in the ISS >15 group remained stable at 9.9%. About half of all injuries occurred outside the ACT. The largest age group represented was 16-24 years. Road trauma was the most prevalent injury mechanism, but its incidence reduced over the 5-year period (52.2-40.3% [P = 0.005]). There was a 3.1% increase in admissions following violence. Conclusion: The largest demographic affected by major trauma in the ACT and surrounds is young people. Injury prevention should remain focused on road trauma but also target violence and high-risk recreation activities. Further investigation around the circumstances of major traumatic injury in young people is required. Funding and cross-border agreements should be reviewed to minimize financial disadvantage to the ACT.