Phlomis species from the Lamiaceae family are widely distributed in Turkey. In this Study, the essential oils of Phlomis russeliana (Sims.) Bentham and Phlomis grandiflora H.S. Thompson var. grandiflora collected from North and Southern parts of Turkey, were obtained by hydrodistillation of the aerial parts. The essential oils were subsequently analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS). The major constituents of P. russeliana essential oil were identified as sesquiterperies beta-caryophyllene (23%), germacrene-D (15%), and caryophyllene oxide (8%). Analysis of P. grandiflora var. grandiflora oil also showed oxygenated sesquiterpenes such as beta-eudesmol (42%) and alpha-eudesmol (16%) as major constituents.