Hydrodistillation of volatile oil from the aerial parts at full flowering stage of Nepeta crassifolia Boiss. & Buhse was analysed by a combination of GC and GC-MS. Twenty-one components were characterized in the oil layer. The main constituents were 4aalpha,7alpha,7aalpha-nepetalactone (92.6%), linalyl acetate (2.6%), piperitone (0.80%), germacrene D (0.73%), 4abeta,7alpha,7abeta-nepetalactone (0.64%) and beta-caryophyllene (0.58%). Copyright (C) 2003 John Wiley Sons, Ltd.