Abstract The composition of the essential oils from two Labiatae species of Iran were analyzed by GC and GC/MS. Î²-pinene (33.8%) and 1,8-cineole (14.7%) were the main components among the 18 constituents characterized in the oil of Cyclotrichium strausii representing 93.2% of the total components detected. Twenty-four compounds were identified in the oil of Phlomis pungens, representing 91.7% of the total oil with germacrene D (24.5%), bicyclogermacrene (14.1%), Î±-pinene (13.5%) and (E)-Î²-farnesene (13.4%) as major constituents. The oil of C. straussii consisted of mainly monoterpenes, while in P. pungens oil sesquiterpenes predominated over monoterpenes.