Abstract The steam distilled oil of the aerial parts of Orthodon dianthera Maxim, (syn. Mosla dianthera Maxim.), obtained in 0.2% v/w on fresh weight basis, was found to contain β-caryophyllene (52.9%) and α-humulene (23.8%). The remainder of the oil consisted mainly of (E)-asarone (5.7%), (Z)-asarone (5.5%), a mixture of mono- and sesquiterpenes and oxygenated compounds Key Word Index: Orthodon dianthera Labiataeessential oil compositionβ-caryophylleneα-humulene