Successful models of inpatient geriatric assessment have often involved long hospital stays, specialized interdisciplinary care, and prolonged follow-up, which are difficult to achieve within a prospective payment system. A randomized clinical trial was undertaken to evaluate the efficacy (maintenance or improvement in mental, emotional, and physical function) of using a geriatric assessment process in acute hospital care without increasing hospital charges or lengths of stay. Four hundred thirty-six patients greater than or equal to 75 years of age were randomly allocated to treatment (n = 221) or control (n = 215) conditions. Patients in the treatment group were admitted to a special unit and evaluated on admission by an interdisciplinary team, which developed a care plan. Although primary care was provided by the patient's own physician, the team followed the patients as consultants on the unit in the hospital, and by telephone for 2 months after discharge. The control group was placed on other units and received usual hospital care. The treatment and control groups were similar at study entry. At follow-up, there were no significant differences between the groups with respect to lengths of stay, hospital charges, mortality, change in physical function, or change in mental function. The treatment group changed more often in measured emotional function (chi 2 = 6.213, P = .045). This study indicates that it is feasible to implement consultative interdisciplinary team care in the acute-care hospital, but that its efficacy may be limited when applied to an unselected group of older patients.