We present the case of a woman who had two severe anaphylactic episodes with hypotension and bradycardia in relation to the administration of general anesthesia. In the allergy evaluation, IgE antibodies to suxamethonium, a muscle relaxant which was used in both procedures, were detected by skin prick tests. No cross-reaction was found to other muscle relaxants derived from quaternary ammonium. The patient was able to be operated on, and did not present any adverse reactions to the use of local anesthesia or to general anesthesia using pancuronium as a muscle relaxant.