A number of studies have questioned the reliability of psychological data collected from those involved in litigation following mild head trauma. This study examines two severely injured groups, one litigant, the other non-litigant, at 4 months and 10 years post injury. No differences were identified between the groups on measures of cognitive ability to suggest underachievement at an early stage of recovery, when the litigant group was assessed medico-legally or after an interval of 10 years post injury. Measures of psychosocial outcome and psychological morbidity at 10 years post injury failed to show any significant differences between the groups, indicating that the process of litigation did not have any long term effects in respect of illness behaviour. The results of this study are consistent with data from another study that assessed litigants and non-litigants after severe head injury, but differs from studies that examine cases of minor injury.