The development of a policy for antimicrobial use on a urological ward is presented. The introduction of guidelines for rational antimicrobial use and the monitoring of their effect over a four-year period are described. As a result of the implementation of this policy, a reduction of over 60 percent in antibiotic consumption on the urological ward was achieved. Without interference in the quality of patient care, as determined by the incidence of postoperative wound infections and adverse effects, the overall number of patients treated with antimicrobial agents was reduced 50 percent, but proved to be age dependent. In addition, costs were diminished 20 percent. These results were achieved by intensive collaboration between the Departments of Urology and Clinical Pharmacy.