The qualitative and quantitative composition of the essential oil from aerial parts of Eupatorium buniifolium Hooker et Arnott (Asteraceae) has been investigated for the first time. The essential oils were obtained by steam distillation of leaves and analysed by GC-MS; 44 components were identified. Monoterpene and sesquiterpene hydrocarbons, especially α-pinene (14.7%), β-elemene (12.2%), germacrene D (11.5%), trans-β-guaiene (6.5%) and (E)-caryophyllene (4.3%), were the major constituents found in the oils. The characterisation of E. buniifolium by enantioselective GC was performed by evaluation of the enantiomeric ratios of α-pinene, sabinene, β-pinene, limonene, terpinen-4-ol and germacrene D. Copyright © 2005 John Wiley & Sons, Ltd.