A patient underwent an operation under general anesthesia which included the use of succinylcholine and intravenously given lidocaine, with assisted respiration. After recovery she gave evidence of having been intermittently conscious during the three-hour period of supposed anesthesia and stated that she had suffered extreme pain during much of the operation. An awareness that such an extreme in pain reflex threshold may rarely exist in patients undergoing operative procedures should caution us to be more appreciative of the subtle signs suggesting an inadequate state of anesthesia. This is particularly applicable when respiratory reflexes and other types of response are obviated by the use of neuromuscular blocking agents.