Delayed awakening from anesthesia poses diagnostic challenges. The time for emergence from anesthesia is affected by patient factors, anesthetic factors, duration of surgery, and painful stimulation. However, delayed emergence can have unusual causes. We report a patient who, following termination of general anesthesia, did not regain consciousness for 6 h following surgery. Vital sign measurements, blood gas analysis, administrations of flumazenil and naloxone, and brain scan ruled out several possible causes for the delayed emergence. Apparently, the delayed emergence was a consequence of hypoperfusion of the brainstem during neurosurgical manipulations. To our knowledge, this is the first reported case of delayed anesthesia recovery on this basis.