A description is given of a technique of anaesthesia suitable for the performance of major arterial surgery in the pig. Paraldehyde, injected inrraperitoneally, enables gaseous induction of anaesthesia to be achieved smoothly, using oxygen and halothane. Muscle relaxants are not used to facilitate intubation and are not required for intra-abdominal surgery. Rapid recovery of consciousness, with early drinking and feeding, is possible after the use of this technique.