Abstract Composition of the water-distilled oil of Phlomis nissolii L., endemic in Turkey, was analyzed by GC and GC/MS. Eighteen compounds were identifed representing 92.6% of the total oil. Germacrene D (33.9%), bicyclogermacrene (15.3%) and (Z)-Î²-farnesene (10.7%) were the main constituents in the oil.