Psychiatric day hospitals for the elderly have been regarded either as an alternative to in-patient care or as a long-term supportive facility for patients with chronic psychiatric disabilities. In a five-year review of such a unit it was found that the unit's main function had become that of providing an immediate short-term supportive facility to demented patients, mainly in the 75-years-and-over age group, and to their relatives, until such time as beds in the long-stay psychogeriatric wards of the hospital became available. The implications of this change in role of day hospitals are discussed in the light of present facilities and the predicted increase in the size of this section of the population.