We investigated the muscular relaxant properties of propofol in a 54 year-old-man with severe tetanus. Four consecutive boluses of propofol 50 mg i.v. were administered. Mean muscular activity recorded on an electromyography (EMG) decreased from 100 to 10-25 mV within 15 s after each bolus. EMG values were restored to prior levels 10 min after the last bolus. Maximum decrease of muscular activity was observed with propofol blood level between 2.90-3.20 micrograms.ml-1. Neuromuscular function recorded by means of evoked electromyography was not affected by propofol administration.