In a double-blind, randomised study of patients scheduled for minor hand surgery 0.5% 2-chloroprocaine (n = 30) and 0.5% prilocaine (n = 30) in a volume of 40 ml were compared for intravenous regional anaesthesia. The onset of sensory and motor block and recovery of sensory block were determined, and the occurrence of side-effects was noted. Twenty-four patients in the 2-chloroprocaine group and 17 in the prilocaine group developed complete sensory block by 15 min after injection (p < 0.05). Complete recovery of sensation was faster after prilocaine (7.1 min) than 2-chloroprocaine (9.8 min) (p < 0.01). Venous irritation and/or urticaria after tourniquet release was observed on 10 occasions in those receiving 2-chloroprocaine and twice in those receiving prilocaine. An increase in heart rate of > 20% above control values occurred in three patients, all of whom had been given 2-chloroprocaine. Clinically, local anaesthetic properties of 0.5% 2-chloroprocaine and prilocaine were similar, but there were more side-effects with the former drug.