To investigate the pattern of medical student teaching about sleep and its disorders in the UK. A questionnaire was sent to organisers of preclinical and clinical courses in which aspects of sleep and its disorders might appropriately be included. All UK medical schools. There was an overall 71% response rate, with all medical schools represented. A wide variation (80-6%) was seen between departments in the provision of such teaching. The median total time given to sleep and its disorders in undergraduate teaching as a whole was five minutes, for preclinical teaching 15 minutes, and zero in clinical teaching. Teaching was particularly limited on the various types of sleep disorder common in clinical practice, and also on non-medication treatments. Little consistency was evident in teaching format, recommended reading, use of other instructional material and student assessment. Awareness of local sleep research or clinics was reported by very few. As in other countries, undergraduate medical teaching is inadequate as a basis for the development of competence in diagnosing and treating sleep disorders, which are common and cause difficulties in all sections of the population. There is a need to correct this deficiency in ways compatible with recent recommended changes in medical education.