Abstract The volatile constituents of the aerial parts of Nepeta kotschyi Boiss. growing wild in Iran have been examined by GC/FID and GC/MS. Eleven components were identifed, constituting approximately 97.7% of the oil. The main constituents of the essential oil were 4aβ,7α,7aα-nepetalactone (92.0%), 1,8-cineole (2.6%), β-pinene (0.9%), pulegone (0.4%) and bicyclogermacrene (0.3%).