The extracts of aerial parts of Achillea clavennae, Achillea holosericea, Achillea lingulata and Achillea millefolium (hexane:ether:methanol=1:1:1) have been tested for antimicrobial activity in a disk diffusion assay against five bacteria (Staphylococcus aureus, Escherichia coli, Klebsiella