Abstract The essential oil from Laggera tomentosa Sch. Bip. ex Oliv. et Hiern (Asteraceae) endemic to Ethiopia was investigated by means of GC, GC/MS and NMR spectroscopy. Forty-nine compounds constituting 94% of the oil were identified. The oil composition was characterized by a high percentage of oxygenated monoterpenes (78%), the major compound being chrysanthenone (58%). Sesquiterpene hydrocarbons constituted 10%, while the monoterpene hydrocarbons and oxygenated sesquiterpenes accounted for 3% each. The high percentage of chrysanthenone and the other main compounds isochrysantenone, filifolone and (Z)-isogeranic acid made the composition of the oil markedly different from those of the other species of the genus.