SUMMARY The parturitional behaviour of full-term rabbits injected with 100 or 200 mu. oxytocin is described. Young were born at rates varying from twelve in 7 min to three in 20 min. Newborn pups suckled the doe while she was still in labour. Labour was induced in full-term does under sodium pentobarbitone anaesthesia by injection of 50–200 mu. oxytocin or by electrical stimulation of the supraoptico-hypophysial tract. Abdominal contractions, milk ejection and delivery of young were recorded kymographically. The delivery of every pup was assisted by reflex straining movements of the doe. Though commonly labour was completed without the secretion of additional oxytocin from the neurohypophysis (as shown by the milk-ejection record), occasionally a reflex release of oxytocin did occur in amounts sufficient to influence the course of labour. In many cases labour appeared to be as efficient as in the conscious animal. Suppression of abdominal contractions by spinal anaesthesia did not prevent effective delivery of young after injection of oxytocin. However, the time taken to expel individual pups from the vagina tended to increase, and the last of the litter was generally retained in the vagina. The physiological mechanisms involved in parturition in the rabbit are discussed in the light of these and earlier findings.