In three clinically depressed patients undergoing repeated electroconvulsive therapy (ECT) with either propofol or methohexitone, dose-dependent decreases in the duration of motor and EEG seizure activity were noted. Use of a 'minimally' hypnotic dose of propofol (0.75-1.0 mg kg-1) was associated with a seizure duration which was comparable to standard hypnotic doses of methohexitone. We conclude that doses of propofol < 1.5 mg kg-1 are associated with a clinically acceptable duration of EEG seizure activity (> 30 s) during ECT.