Many different drugs are used for sedation of patients in the intensive care unit (ICU). The vast majority of the agents used are administered intravenously; however, for the purposes of sedation, inhalational anaesthetic agents have some advantages, and potential disadvantages, over intravenous drugs. There has been some published work on the use of isoflurane as a sedative agent in this situation, with favourable comparisons with the currently used intravenous drugs. Ultimately, the role of inhalational agents as sedatives in the ICU will depend on the development of appropriate equipment and the enthusiasm of the clinicians involved.