To describe the incidence, characteristics, outcomes and hospital costs of patients admitted to hospital following trauma in a health region in Aotearoa New Zealand over a 10-year period. A retrospective, observational study used data from the Te Manawa Taki (TMT) regional trauma registry to identify patients of all ages and injury severities that were admitted to hospital following injuries from 2013 to 2022, inclusive. This study reports on incidence of injuries with regard to age, gender, ethnicity, injury severity score (ISS), injury characteristics and direct cost to TMT facilities. Searches identified 60,753 trauma events leading to patient admission to hospitals in the TMT region. Of these, 81.9% were low-severity trauma, 10.2% were moderate-severity trauma and 7.9% were high-severity trauma. There were statistically significant relationships between gender, ethnicity and ISS category. Males were more likely to be hospitalised for any traumatic injuries. High-severity trauma is dominated by road traffic injuries and low-severity trauma is dominated by falls. Advanced age was associated with higher injury severity. The direct cost of trauma care to TMT hospitals increased by 122% during the 10-year period. The study has identified the incidence, demographic features, severity, costs and outcomes for trauma patients admitted to hospitals in the TMT region of Aotearoa New Zealand over a continuous 10-year period. The volumes and costs of injury represent a significant burden on the health system, individuals and communities. Detailed understanding of the causes and costs of injuries of all severities will inform prevention activities, clinical quality improvement and health service planning.