abstract the essential oil isolated from the aerial parts of gredos' camomile (santolina oblongifolia) by hydrodistillation has been analyzed by gas chromatography and gas chromatography coupled to mass spectrometry. the essential oil composition was very complex. a total of 94 compounds have been identified, all of which with percentage compositions lower than 10%. the main constituents of the oil were identified as borneol (8.8%), cis--guaiene (5.9%), myrcene (5.4%), limonene (5.2%), -oplopenone (4.7%) and -pinene (4.5%). monoterpene and sesquiterpene compounds were present in similar amounts in the oil (37.0% and 35.3%, respectively). most monoterpenes were hydrocarbons (20.1%) while in the sesquiterpene fraction was predominated by oxygenated compounds (22.6%). a new possible bejarol isomers and a bejarol derivative have been detected in low amounts.