The essential oils of leaves and flowers Achillea wilhelmsii (compositae) collected from the suburb of Neka, north of Iran, in June 2001, were isolated by hydrodistillation and analyzed by means of GC and GC/MS. Fifteen and nineteen components were identified in the oils of the leaves and flowers of Achillea wilhelmsii, respectively. The major constituents of the essential oil of the leaves of A. wilhelmsii were camphor (24.1%), 1,8-cineole (22.3), borneol (11.1) and myrtenol (8.5%). The major constituents of the essential oil of the flowers of A. wilhelmsii were camphor (21.2%), myrtenol (14.4%), myrtenyl acetate (8.9%), yomogi alcohol (8.7%) and borneol (8.2%).