Abstract Samples of essential oils from leaves of Mikania hirsutissima DC, M. involucrata Hook, et Am. and M. laevigata Shultz Bip. ex Baker were analyzed by a combination of capillary gas chromatography and GC/MS. Forty one components have been identified representing 70â95% of the oils content. The oils of M. involucrata and M. laevigata are quite similar and constituted by sesquiterpenes, represented mainly by Î²-caryophyllene (18.9% and 20.9%), germacrene D (9.9% and 29.8%) and bicyclogermacrene (28.1% and 13.4%). The oil of M. hirsutissima is also characterized by sesquiterpenes, and the major components are ar-curcumene (15.0%) and spathulenol (10.2%), and a small fraction (6.5%) of aliphatic compounds.