Hostels for the homeless contain many who are disabled by chronic mental illness but have little access to rehabilitation services. One approach to solving this problem might be to measure the needs of hostel residents in a standardized way and use this information as a basis for planning interventions. This study attempted to use the MRC Needs for Care Assessment Schedule to measure the needs of 46 mentally ill residents of Oxford hostels. It aimed to determine if a standardized assessment could be used in these difficult settings and if the needs it identified could form a useful basis for planning future interventions. Although it was possible to use the schedule, and although the pattern of need identified appeared broadly to reflect conditions in the hostels, it was not felt that the information produced was of sufficient quality to assist in planning services. The authors postulate that underlying this deficiency is the failure of the schedule to take sufficient account of the views of staff and residents.