© 2020, Badebio Biotechnololgy Ltd. All rights reserved.The genus Achillea L. (Asteraceae), which is commonly known as “yarrow”, is mainly distributed in the Northern hemisphere. Turkey is one of the most important centers of diversity for the genus in the world. Many species of the genus Achillea have been known since the times of Dioscorides and used in the folk medicine to treat various illness and disorders in our country. In this study, the aerial parts of the endemic Achillea teretifolia Willd. collected from Afyon were investigated for essential oil composition. Hydrodistilled essential oil obtained from the aerial parts of the plant was analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Forty-eight compounds were identified representing 71.5% of the total oil, 1,8-cineole (16.1 %), camphor (12.7 %), p-cymene (10.6 %) and terpinen-4-ol (6.1 %) were characterized as the main constituents.