Intraoperative neurophysiological monitoring (IONM) has been widely used to minimize the risk of postoperative neurological deterioration in spinal surgery. In this case, a neural damage was prevented by detecting the patient's postural abnormality through IONM ahead of the initial surgical incision. A 29-year-old man underwent surgery due to cervical myelopathy induced by herniated cervical disc at C5/6 level. After the setting of the IONM, baseline waves of evoked potentials were obtained except the wave of motor evoked potentials (MEPs) in right abductor pollicis brevis muscle. After a prompt check, it was confirmed that the patient's neck was excessively flexed, and the patients neck position was corrected to the neutral. Afterwards, the MEP waves appeared, and it was not significantly changed until the surgical wound closure. There was no postoperative neurological deterioration. Thus, IONM should be continuously performed even ahead of the initial surgical incision to confirm the factors affecting patients’ neural compromise.