The paper describes the work of an assessment unit setup to provide a service for frail elderly patients admitted to general medical units at the Royal Infirmary of Edinburgh during the period of April 1989 to March 1990. Patients were selected on the basis of diagnosis, mental and physical function, age and social background and transferred to the assessment ward within 24 hours of admission to a medical ward. Most of the 376 patients admitted to the ward had a high level of multiple pathology and physical incapacity and a third had an acute confusional state. The mean length of stay was 19.4 days. There was a 13% mortality with 71% of survivors returning to their own homes. Review of mobility and self care capacity of the group revealed a striking increase in function during their stay in the ward. Factors increasing the likelihood of discharge included having a spouse, receiving support at home, having a low initial dependence rating. Adverse factors included having cerebrovascular disease, having dementia and initial maintenance of urine and faeces.