A local anesthetic agent which is most commonly used for outpatients is lidocaine hydrochloride that contains epinephrine, which is for vasoconstriction in 1:100,000 concentration. This agent is known as a safe local anesthetic agent and has been used widely for topical use or injections. However, the allergic reaction that we will report in this case occurred when common local anesthesia was done intraorally, and the patient complained of hyperventilation, tachycardia, abdominal pain and unintentional tears. We experienced an allergic reaction after injecting the lidocaine hydrochloride and therefore report the case to suggest that local anesthesia should be always carried out very carefully.