Sleep complaints were obtained from 22 hospitalised patients with traumatic brain injury of recent onset (median 3.5 months after injury) and were compared with those of 77 discharged patients who had sustained brain injury about two to three years (median 29.5 months) previously. A high incidence of sleep complaints was noted in both groups (72.7% and 51.9% respectively). Disorders in initiating and maintaining sleep (DIMS) were the most common complaints among hospitalised patients (81.2%), whereas disorders of excessive somnolence (DOES) were common in discharged patients (72.5%). This difference in the nature of the complaints was apparently due to differences between the two groups in the time elapsed since injury, duration of coma, and immediate environmental conditions. In discharged patients with sleep complaints, neuro-behavioural impairments and a poorer occupational outcome were more common than in those discharged patients without sleep complaints. It is suggested that early evaluation and treatment of sleep disturbances must be considered an integral part of the rehabilitation process.