© 2018, İstanbul Medipol University. All rights reserved.Chemical composition of the essential oils obtained by hydrodistillation from the aerial parts of Achillea biebersteinii Afan. and A. wilhelmsii C. Koch were analyzed by GC-FID and GC-MS. The essential oils of A. biebersteinii and A. wilhelmsii were characterized by the presence of a high percentage of oxygenated monoterpenes 72.9% and 49%, respectively. Sixty-four compounds were identified in the essential oil of aerial parts of A. biebersteinii representing 95.9 % of the essential oil. The main components of A. biebersteinii essential oil were 1,8-cineole (34.6%) and camphor (12.9%). Fourty-two compounds were identified in the essential oil of aerial parts of A. wilhelmsii representing 88.2 % of the essential oil. Main component of the essential oil of A. wilhelmsii was determined as camphor (32.0%).