Abstract Water-distilled essential oils from the aerial parts of Ferula szowitsiana DC. (syn. F. khorasanica Rech. F. et Aell. and F. microloba Boiss.), Artedia squamata L. and Rhabdosciadium petiolare Boiss. et Hausskn. ex Boiss., the last of which is endemic to Iran, were analyzed by GC and GC/MS. Twenty-three components representing 100% of the oil of F. szowitsiana were identified of which Î±-pinene (12.6%), germacrene D (12.5%) and Î²-pinene (10.1%) were found to be the major constituents. The oil of A. squamata was characterized by its richness in Î±-pinene (79.9%) among the 25 components comprising 99.6% of the total oil detected. Germacrene D (48.6%) was the main component among the 17 constituents characterized in the oil of R. petiolare representing 88.7% of the total components detected.