AbstractEnantiomeric ratios of linalol in Italian sweet orange oils, Italian and foreign bitter orange oils, Uruguayan mandarin oils and mixtures of sweet and bitter orange oils are reported. A fully automatic on‐line HPLC–HRGC system which allows the detection of the enantiomeric ratio without interference was used.The results are useful to distinguish bitter orange from sweet orange oils and European (Spain and Italy) from Brazilian and Ivory Coast bitter orange oils; moreover these results give information about the cultivars of mandarin and sweet orange oils from which they have been extracted.