Abstract The oil of a wild growing population of Achillea asplenifolia Vent, was studied for yield, composition and antibacterial activity. The major components in the oil were Î²-caryophyllene (17.6%), germacrene D (15.6%) and chamazulene (13.3%). In an antibacterial diffusion assay, the oil showed activity against all tested Gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa) and Gram-positive Staphylococcus aureus.