There are few reports on aggravation of asthma by mint flavor although it is a common ingredient of many products. A 40-year-old male patient with aspirin-sensitive asthma experienced anaphylaxis after using a gargle that contained mint flavor. Skin prick tests and ELISA for serum specific IgE to mint showed negative responses. Challenge tests with mint oil and menthol were positive and the immediate bronchoconstriction that mast cells may be involved in the pathogenesis of mint-induced asthma or anaphylaxis. To our knowledge, this is the first case of mint-induced anaphylaxis. It is important to alert physicians to the possibility of aggravation of asthmatic symptoms or the development of anaphylaxis by mint flavor.