A case of an anterior spinal artery syndrome complicating an anterior spinal fusion is reported. Besides documenting a relatively rare complication of anterior spinal surgery, the level of the lesion (T6) and the association of spinal shock are relatively unusual. Intraoperative somatosensory-evoked potentials (SEP) deteriorated only transiently and failed to reflect adequately the neurologic injury either intraoperatively or postoperatively. The shortcomings of SEP monitoring are discussed, and the recommendation is made to use the combination of SEPs with the wake-up test when possible.