The compositions of the essential oils of four species of Artemisia (A. kopetdaghensis Krasch ex. Poljakov, A. austriaca Jacq., A. oliveriana J. Gay ex. Besser, A. diffusa Krasch ex. Poljakov), endemic of Iran, were studied by means of GC–MS and GC–FID, using the internal standard method and relative response factors. Around 150 compounds were determined in total, representing 82.1 g/100 g in A. austriaca, 57.4 g/100 g in A. kopetdaghensis, 84.1 g/100 g in A. diffusa and 71.6 g/100 g in A. oliveriana, respectively. Copyright © 2009 John Wiley & Sons, Ltd.