In this research, essential oil yield and composition, total phenolic, flavonioid content and antioxidant activity of eightAchillea(A. vermicularis,A. nobilis,A. wilhelmsii, A. millefolium,A. filipendulina,A. tenuifolia,A. biebersteiniiandA. eriophora) species were compared. The essential oil yield of the leaves ranged from 0.35 % inA. wilhelmsiito 1.5 % inA. biebersteinii. GC-MS analyses revealed 40 compounds in leaves of eightAchilleaspecies. The main constituents were 1,8-cineole, germacrene-D, camphor, borneol and spathulenol. Total phenolic content (TPC) varied from 13.56 inA. biebersteiniito 188.66 mg/1g of dry weight inA. wilhelmsiiwhile, total flavonoid content (TFC) ranged from 19.23 inA. eriophorato 79.16 (mg Quercetin/gdW) inA. biebersteinii. Antioxidant activity of methanolic extract was evaluated according to 1,1-diphenyl-2-picrylhydrazy (DPPH), ferric thiocyanate (FTC) and β-carotene-linoleic acid assay. In DPPH assay,A. eriophorashowed the highest Ic50(1172 µg/ml), whileA. biebersteiniipossessed the lowest one (179 µg/ml). For reducing power, the highest and the lowest absorbance in 700 nm belonged toA. tenuifolia(2.311) andA. wilhelmsii(0.306), respectively. Cluster analysis ofAchilleaspecies based on their major secondary metabolites were also classified the species in to three groups. Finally, comparison of studied species introducedA. biebresteiniias a good source of essential oil, flavonoid content and high antioxidant activity. [ABSTRACT FROM AUTHOR]