Background Traumatic injury is a leading contributor to the overall global burden of disease. However, there is a worldwide shortage of population data to inform understanding of non-fatal injury burden. An improved understanding of the pattern of recovery following trauma is needed to better estimate the burden of injury, guide provision of rehabilitation services and care to injured people, and inform guidelines for the monitoring and evaluation of disability outcomes. Objective To provide a comprehensive overview of patient outcomes and experiences in the first 5 years after serious injury. Design This is a population-based, nested prospective cohort study using quantitative data methods, supplemented by a qualitative study of a seriously injured participant sample. Participants All 2547 paediatric and adult major trauma patients captured by the Victorian State Trauma Registry with a date of injury from 1 July 2011 to 30 June 2012 who survived to hospital discharge and did not opt-offfrom the registry. Analysis To analyse the quantitative data and identify factors that predict poor or good outcome, whether there is change over time, differences in rates of recovery and change between key participant subgroups, multilevel mixed effects regression models will be fitted. To analyse the qualitative data, thematic analysis will be used to identify important themes and the relationships between themes. Contribution to the field The results of this project have the potential to inform clinical decisions and public health policy, which can reduce the burden of non-fatal injury and improve the lives of people living with the consequences of severe injury.