One hundred patients who were referred consecutively to two geriatric day hospitals were followed for 3 months, to determine the efficiency and effectiveness of day hospital management. Transport was highly efficient; only one in every 40 attendances failed because of transport. Selection of patients may have been less efficient, in that only half completed planned treatment. In most cases this was because of progression of the illness. Time at the day hospital was on the whole efficiently used, in that three-quarters of the time was devoted to programmed activities. The effectiveness of the day hospital was limited. In only about one-third of referred patients were the objectives set by the doctor attained. Likewise only one-third of patients felt that they had improved, and one-third of carers experienced relief of strain.