Isoflurane produces unconsciousness by its action on the central nervous system. It has little or no analgesic properties.

Like other inhalation general anaesthetics of the group of halogenated hydrocarbons, isoflurane depresses the respiratory and cardiovascular systems. Isoflurane is absorbed on inhalation and is rapidly distributed via the bloodstream to other tissues, including the brain. Its blood/gas partition coefficient at 37 °C is 1.4. The absorption and distribution of Isoflurane and the elimination of non-metabolised isoflurane by the lungs are all rapid, with the clinical consequences of rapid induction and recovery and easy and rapid control of the depth of anaesthesia.

Metabolism of isoflurane is minimal (about 0.2%, mainly to inorganic fluoride) and almost all of the administered isoflurane is excreted unchanged by the lungs.