Anaesthesia for newborn infants is rarely undertaken in hospitals which have no paediatric surgical department. Using the usual anaesthetic equipment for children on newborns involves many hazards, mainly because of the small respiratory volumes of these little patients, the danger of large deadspace and the high resistance of valves in the equipment. A resuscitation bag for newborns proved to be easy and safe as anaesthesia apparatus, if connected to the output of the anaesthetic machine. Blood gases and respiratory volumes were measured in 17 newborn infants (body weight 1,600 g to 5,280 g) during anaesthesia using endotracheal tubes, masks, controlled and spontaneous respiration.