Background: Most of what we know about the psychiatric consequences of injury is limited to the first year. Determining the prevalence of and risk factors for psychiatric morbidity beyond one year will aid service development and facilitate timely diagnosis and treatment. The aim of this prognostic study was to determine the prevalence of mental disorders in the three years following serious injury and to identify risk factors for the onset of new disorders after 1 year. Methods: Of 272 patients assessed in hospital following serious injury, 196 (72.1 ) were reassessed at 3 years. Assessment involved gold standard semi-structured interviews for psychiatric diagnoses, risk factors for mental disorder, injury measures and pain scores. Results: More than a quarter of all patients were diagnosed with at least one mood or anxiety disorder at some stage during the three years following their injury. The most common diagnoses were major depression (20.0 ), generalised anxiety disorder (6.7 ) and panic disorder (6.7 ). For a third of these patients, the disorder appeared after 12 months, for which persistent physical disability was an independent risk factor. Conclusion: Although there is a necessary focus on the early detection and treatment of mental disorders after injury, attention to later onset disorders is also required for those with persistent pain and physical disability.