To determine the reliability of rapid screening by clinically derived geriatric criteria in predicting outcomes of elderly hospitalized patients. Prospective cohort study of 985 patients screened at the time of hospital admission and followed for 1 year with respect to the outcomes of mortality, hospital readmission, and nursing home utilization. Palo Alto Veterans Affairs Medical Center, a tertiary care teaching hospital. Male patients 65 years of age and older admitted to the Medical and Surgical services during the period from October 1, 1985 through September 30, 1986. Patients were grouped by specific screening criteria into three groups of increasing frailty: Independent, Frail, and Severely Impaired. Each criterion focused on a geriatric condition and was designed to serve as a marker for frailty. Increasing frailty was significantly correlated with increasing length of hospital stay (P less than 0.0001), nursing home utilization (P less than 0.0001), and mortality (P less than 0.0001). Multivariate analyses revealed that the clinical groups were more predictive of mortality and nursing home utilization than were age or Diagnosis-Related Groups (DRGs). Rehospitalization was unrelated to age, clinical group, or DRG, suggesting that utilization may not be driven by the clinical factors measured in this study. Rapid clinical screening using specific geriatric criteria is effective in identifying frail older subjects at risk for mortality and nursing home utilization. Our findings suggest that geriatric syndromes are more predictive of adverse outcomes than diagnosis per se. This well operationalized screening process is inexpensive as well as effective and could easily be introduced into other hospital settings.