AbstractThe principal spectroscopic properties of the four dihydrocarveol diastereoisomers are reinvestigated. The interpretation of their1H‐NMR spectra allows unambiguous differentiation of the diastereoisomers and the determination of their conformations. ‘Negative ion chemical ionization‐Collision‐induced dissociation’ experiments have been performed on the quasimolecular ions [M ‐ H]−using a FT‐ICR spectrometer. The daughter ion spectra of the alkoxide negative ions [M ‐ H]−of the four isomers show substantial differences which can be used for a diastereoisomeric differentiation and the confirmation of the conformations. The gas phase FT‐IR spectra are recorded. The MS and IR results can be used for essential oil analysis using GC–MS an