Abstract The essential oil obtained by hydrodistillation from the leaves and twigs of 'Straggly Baeckea' [Ochrosperma lineare (Myrtaceae)] growing wild in eastern Australia was investigated by GC and GC/MS. One southern chemical form, which yielded 0.3% oil on a fresh weight basis, was found to be rich in methyl chavicol (81.6%), with α-pinene (1.1%), β-pinene (8.3%) and bicyclogermacrene (3.6%) as the only other significant constituents. The more typical northern form yielded 0.1% of a more complex oil found to be rich in bicyclogermacrene (27.4%), β-pinene (21.5%), germacrene D (13.2%) and β-caryophyllene (11.6%) Key Word Index: Ochrosperma lineare Baeckea linearis Myrtaceaeessential oil compositionmethyl chavicolbicyclogermacreneβ-pinenegermacrene Dβ-caryophyllenechemical variation