Previous studies have highlighted the burden placed on family members and close partners of individuals who have sustained traumatic brain injury. This burden of stress has been attributed to the neurobehavioural sequelae of such injuries. However, the extent to which brain injury affects marriages and close relationships has never been statistically evaluated. This study looked at 131 adults with traumatic brain injury in order to determine the incidence of divorce/separation; 49 per cent of our sample reported that they had divorced or separated from their partners during a 5-8-year period following brain injury. Factors which may predict the outcome of relationships include severity of injury (as determined by length of post-traumatic amnesia), length of relationship, and time since injury. The influence of these factors in determining the risk of relationship breakdown is discussed.