One hundred out-patients, referred to a multidisciplinary pain clinic for the management of chronic pain, were questioned regarding their sleeping habits and were grouped according to whether they reported 'good,' 'fair' or 'poor' sleep. All patients were administered questionnaires to measure illness behaviour, depression and anxiety. Information was also obtained regarding the site, intensity and quality of pain as well as amount of general activity. 'Good' and 'poor' sleepers were found to differ on most measures, particularly depression, pain intensity, activity levels and hypochondriasis. These findings suggest that reported sleep disturbance may provide an index of impairment and act as an indicator of psychological disturbance in chronic pain patients.