The problem of the care of the psychiatrically ill aged is large, and will increase. A comprehensive psychiatric service for the aged should cater for various types of patients, and should be conceptualised in terms of a whole community. It involves, in the first place, a sorting operation - patients who need purely residential care and medical treatment must be separated from those who require special psychiatric services. The setting up of a psychogeriatric assessment unit is a priority, followed by the provision of facilities to meet the needs of special patients. These include a small day hospital, beds for inpatients and a community service. The latter is central to any organisation of psychogeriatric services. The provision of new services should grow in association with and, perhaps, out of, existing facilities, and should aim at providing a comprehensive scheme.