Abstract The essential oil of Marrubium astracanicum Jacq. growing wild in Iran was obtained by hydrodistallation and analyzed by GC and GC/MS. Seventy-two components representing 86.5% of the total oil were identified. The main components of the oil were Î²-caryophyllene (21.2%) and valeranone (5.4%). Key Word Index: Marrubium astracanicum Labiataeessential oil compositionÎ²-caryophyllene