Abstract The essential oil of the aerial parts of Centaurea calcitrapa from Algeria was obtained by steam distillation in yield 0.01% and first time analyzed by GC-FID and GC/MS techniques. Over 60 compounds were identified, representing 77.7% of the total components detected. The major constituents were Î²-caryophyllene (5.3%), 6,10,14-trimethyl-2-pentadecanone (4.7%), (Z)-Î²-farnesene (4.2%) and heptanal (4.2%). These results show remarkable qualitative and quantitative differences with previously reported studies for Centaurea calcitrapa.