Intraoperative neurophysiologic monitoring is used for monitoring and mapping of neurological structures during surgery and procedures where the neurological structures are at risk. Among the most commonly used techniques are electrophysiologic techniques, which include spontaneous and evoked electromyography, somatosensory evoked potentials, motor evoked potentials, electroencephalography, and auditory brainstem responses. These methods differ in their responses to anesthesia and in their clinical contribution to monitoring because of differing anatomy. Their use in spinal corrective surgery highlights the role of the anesthesiologist during cases when these techniques are utilized. Optimization of anesthesia, position, and physiology provide better monitoring conditions, enhance signal evaluation, and may lead to better neurological outcome.