The water-distilled essential oils ofThymbra sintenisiiBorn, et Aznav. subsp.isauricaP.H. Davis andOriganum leptocladumBoiss., both Turkish endemic species, were analyzed by GC and GC/MS. Thirty-two compounds were characterized in the oil ofT. sintenisiissp. isaurica representing 96.64% of the oil, while 29 compounds were characterized inO. leptocladumoil representing 92.80%. The major components ofT. sintenisiioil were carvacrol (39.01%), p-cymene (26.38%) and γ-terpinene (12.68%). The oil ofO. leptocladumalso contained p-cymene (47.09%) and carvacrol (14.61%) as major components along with borneol (10.80%).