Abstract The chemical composition of the essential oil obtained from Artemisia copa growing in the high valley region of Bolivia, Province of Cochabamba, was determined by a combination of GC and GC/MS measurements. The main constituents were Î²-thujone (42%), chamazulene (6.5%) and a homoterpene (6.0%) as well as limonene (5%) and Î±-pinene (4.8%).