Changes in emotional and social behaviour are relatively common following severe traumatic brain injury (TBI). Despite the serious consequences of these changes, little is known about the underlying neuropsychological deficits. In this study, we investigated which deficits might underlie these behavioural changes. The emotional and social behaviour of 17 patients with severe TBI was assessed with questionnaires, completed by the patient and a relative. Neuropsychological tests assessed recognition of emotional expressions, understanding of other people's mental states and cognitive fluency. Ratings from patients and relatives revealed changes in emotional and social behaviour after injury. Compared to matched healthy controls, the patients were impaired at recognising facial and vocal expressions of emotions, detecting social faux pas and nonverbal fluency. None of these impairments was significantly associated with the relatives' ratings of behavioural problems following TBI, although the correlation with detecting social faux pas was relatively high ( r =-.61).