Detailed knowledge of the pharmacology of the intravenous anaesthetic agents--a relatively-small group of drugs--is necessary to achieve optimal results in a diverse patient population. The trend towards short-stay surgery requires a consideration of the speed of recovery from anaesthesia, as well as the quality of that recovery, more than ever before. New agents, particularly propofol, have expanded the potential for total intravenous anaesthesia, but technical developments in drug delivery are needed for the full realization of the properties of these drugs.