Because of increasing norfloxacin use and the development of resistant organisms, an evaluation was undertaken in a University Hospital to assess the appropriateness of norfloxacin for the treatment of urinary tract infections and to calculate the potential cost savings associated with more cost-effective antibiotic therapy. Medical records of 64 patients receiving norfloxacin for a 31-day period were concurrently reviewed. Of these, 58 patients were treated for urinary tract infections and four patients received urinary tract infection prophylaxis. Fourteen patients were prescribed solely empiric therapy whereas an additional 44 patients received definitive treatment confirmed by culture results. Based on the predetermined criteria, norfloxacin use for the definitive treatment of urinary tract infections was deemed to be appropriate in 34 of the 44 patients. Three additional courses of therapy were also judged to be appropriate due to documented signs and symptoms associated with urinary tract infections, despite cultures with less than 10(5) colony forming units per mL urine. Reasons for inappropriate use in the remaining seven patients included isolation of fewer bacteria than required by the criteria in asymptomatic patients (3 cases), isolation of organisms not sensitive to norfloxacin (1 case) and lack of dosage adjustment for renal insufficiency (3 cases). Nineteen of 32 evaluable inpatients (59%) received norfloxacin when a less expensive, equally effective agent was available. Although savings from more cost-effective therapy of urinary tract infections are minimal, due to the potential emergence of resistant organisms, norfloxacin should be reserved for infections not amenable to treatment with other oral antibiotics.