Generally a patient who was injected radiopharmaceuticals for nuclear medicine examination is not an object of isolation. Therefore, when the patient uses toilet, we expect surface contamination of a toilet by radioisotope. The measured value is 25.69Bq/cm2(a restroom near admission and administration), 19.39Bq/cm2(a toilet near department of radiology). The study shows that 9 of 24 locations in controlled area exceed over surface contamination limit. From now on, we should find source of contamination through measurement radioactive nuclide to apply radiation safety management.