Transcranial electrophysiological monitoring during neurosurgery can help surgeons timely and comprehensively judge the integrity of neurological function of patients under anesthesia, improve the decision‑making power of surgical operators and ultimately reduce the rate of disability incidence during operation. Although arousal test is widely used, this kind of monitoring is not risk free. Actually, the tongue bite injury is the most possible complications. The incidence is up to 0.63%. In this paper, a case with tongue bite during motor evoked potential monitoring was reported. The causes were analyzed based on published literatures to reduce the incidence of complications in transcranial electrophysiological monitoring surgery.