Abstract The flowers of Phlomis fruticosa L., Lamiaceae were collected in Kythnos island, Aegean sea, Greece. The essential oil was obtained by hydrodistillation of these flowers and was analyzed by GC/MS. Thirty seven components were identified representing 85.6% of the oil. The main components were germacrene D (17.8%), Î³-bisabolene (12.6%), Î±-pinene (8.9%), Î²-caryophyllene (8.7%).