Saffan was injected intravenously on 41 occasions in 11 horses and ponies to investigate its possible use in clinical equine anaesthesia. The optimum dose for induction was 1-90 mg per kg. This dose was divided into two halves, the first half given in five seconds and the second half, containing suxamethonium chloride 0.1 mg per kg, in the next 10 seconds. Induction was associated with excitement for up to 30 secs after the assumption of recumbency. At this dose rate anaesthesia lasted five to eight minutes. Muscle relaxation was poor. Recovery was associated with marked tactile and audible hyperaesthesia. Slight stimulation resulted in twitching and violent kicking movements lasting up to 15 mins. Maintenance with halothane was satisfactory and recovery from this regime was uneventful. Anaesthesia could be maintained with Saffan alone. This agent would appear to offer no advantage over currently used anaesthetic agents in equine practice and to display several marked disadvantages.