Gas chromatography-olfactometry (GC-O), gas chromatography-mass spectrometry (GC-MS) and preparative column chromatography were used to identify the key odorants present in laboratory-extracted clementine, oil from Spain. Almost 50 odorants were identified using GC-O, many of which were unsaturated aldehydes with high odour spectrum values (OSV). alpha- and beta-sinensal, trans-4,5-epoxy-(E)-2-decanal, (E,Z)-2,6-dodecadienal and linalool were found to dominate clementine oil aroma. Enrichment of the oxygenates using preparative column chromatography provided further identification of a total of 50 aldehydes, not all of which were present in the oil at concentrations high enough to produce a response using GC-O. Aldehydes contributed approximately 80% of the total aroma of clementine oil. New odorants not previously reported in clementine oil include many unsaturated aldehydes, trans-4,5-epoxy-(E)-2-decenal, trans-4,5-epoxy-(E)-2-dodecenal, 4-hydroxy-2,5-dimethyl-3(2H)furanone (furaneol), 3-hydroxy-4,5-dimethyl-3(2H)-furanone (sotolon) and 1,8-cineole. No single odorant emerged as being characteristic of clementine oil aroma. Copyright (C) 2003 John Wiley Sons, Ltd.