We used the Appropriateness Evaluation Protocol (AEP) to evaluate appropriateness of admission and continuing hospitalization (daily till discharge of maximally till 15th day of hospitalization) of 260 patients admitted consecutively to department of internal medicine of a teaching hospital. Reasons of inappropriate admissions and delayed discharges were classified and analyzed. Results of the valuation of some patients were subject to control by a committee of fully specialized hospital physicians. 63 (24%) of 260 admissions and 1005 (54%) of 1869 evaluated days of stay failed the AEP criteria. These patients could be well served by lower treatment intensity in outpatient clinics, nursery homes or their own homes. Such a shift in pattern of provided care requires profound organizational changes many of which are out of reach of individual acute hospitals. Despite some limitations we find AEP a useful tool for internal utilization review. External application of AEP in a representative sample of acute care hospitals could provide important data for future development of the Czech health care system.