Constituents of the essential oil of Achillea wilhelmsii L. growing wild in Kerman-Iran were studied by TLC, GC, and GC/MS methods. The main components of the monoterpene fraction of the oil were camphor, borneol, linalool, 1,8-cineole, chrysanthenol acetate, and carvacrol. The percentage of the identified sesquiterpenoid components was relatively high and constituted 29% of the oil.