A 37-year-old male was admitted for a hemorrhoidectomy. He received uneventfully spinal anesthesia for a hemorrhoidectomy. He had no previous history of any allergic tendency. By the request of the general surgeon, a cefotetan was intravenously administered slowly to reduce the incidence of infection. A few minutes later, anaphylactic reaction developed with hypotension, tachycardia, consciousness change and urticaria. After appropriate management, he recovered without any complication.