Five motor and six cognitive tests were performed once before and then serially after anaesthesia with halothane and nitrous oxide of both short and long duration, methohexitone anaesthesia, and diazepam sedation with local anaesthesia. An untreated control group was also tested. The results suggest that, in the first hour, recovery was most rapid after short-duration halothane and nitrous oxide, was less rapid after methohexitone alone and was least rapid after long-duration halothane and nitrous oxide. Recovery after diazepam with local anaesthesia was prolonged and was incomplete at 3 h.