Post-operation vestigial remnant of surgical instruments is a very serious problem in the operating room. The current two-dimensional symbol system is being used to help manage this problem. However, the two-dimensional symbols of this system have to be identified one at a time, since the symbols are a sort of printed matter. An HF band passive RFID system was also proposed to help manage surgical instruments. This system also had problems in identifying the signals of a large number of surgical instruments in bulk, since the scope of its identification area as a detection area was relatively small. To improve the deficiencies of this system, a UHF band passive RFID system was developed to identify the signals of all the surgical instruments, since its identification efficiency was far better than that of the HF band RFID system. From the results of our experiment using 100 surgical instruments, all the instruments were identified in approx. 15 seconds with this new RFID system. The electrical field intensity was also kept at a low, safe level, maintaining the working integrity of any electronic device within the operating room. These results are very promising and indicate that the proposed RFID system will be an improvement to the surgical instrument management systems currently being used. This new system will also undoubtedly reduce the workload of surgical nurses, while reducing human error in the operating room.