Tanacetum species are consumed as tea in Turkey. We comparatively evaluated the phytochemical potentials and antioxidant activities of the essential oil and methanolic extracts of Tanacetum cilicicum. The chemical constitutes of T. cilicicum essential oil and antioxidant activity of this species was analysed by gas chromatography–mass spectrometry (GC–MS) method. Bicyclo (3,1,1) hept-2-en-4-ol (21.92%), camphor (15.56%) and 1,8-cineole (13.45%) which are oxygenated monoterpenes were found as the major constituents. Phenolic acids and flavonoids were quantificated by HPLC–UV. Catechin was found as the main component. The essential oils and methanolic extracts were evaluated by antioxidant activities. The leaves exhibited significant metal chelation activity with a value of 20.75 ± 4.63 μg/mL.