The essential oil from the different parts (inflorescences, stems+leaves and roots) of E. corniculatum Lam. gathered in Guadalajara (Spain) has been extracted by steam distillation and analysed by gas chromatography and gas chromatography coupled to mass spectrometry. Quantitative and qualitative differences have been found between the analysed parts, although all of them contained the same principal compound, 2,4,6-trimethylbenzaldehyde, representing the 50.8%, 50.0%, and 29.8% of the total oil for inflorescences, stems+leaves and roots, respectively. Other representative constituents of the oil were similar in the different fractions: in the inflorescences compounds were found to be alpha-pinene (4.0%), chrysanthenyl acetate (4.0%), 2,4,5-trimethylbenzaldehyde (3.3%), (2Z,6E)-farnesol (2.0%), (E)-nerolidol (2.1%) and (Z)-beta-ocimene (2.1%), while the stems+leaves oil showed 2,4,5-trimethylbenzaldehyde (3.8%), alpha-pinene (3.4%), (E)-nerolidol (2.4%) and (2Z,6E)-farnesol (2.1%), and in the roots oil a phyllocladene isomer (13.0%), (E)-nerolidol (9.4%), beta-eudesmol (4.1%) and (2Z,6E)-farnesol (2.1%) were found. The presence of C-10 compounds as the main fraction for an Eryngium species is worth mentioning. This is the first report on the chemical composition of this Mediterranean endemic species.