A portable version of the Glostavent anaesthetic machine is described in which recent developments in draw-over technology are incorporated into a traditional draw-over anaesthetic system. The additional features include a more efficient reservoir and an improved vaporiser which have enhanced the performance and versatility. The portable Glostavent weighs less than 10 kg and is transported in a container the size of a small suitcase. It can be used to provide inhalational anaesthesia safely and economically in situations where there are no support facilities. It is ideal for use in battlefield or disaster situations and in isolated hospitals in disadvantaged regions of the world.