The enantiomeric distribution of beta-pinene, sabinene, limonene, linalool, terpinen-4-ol, and alpha-terpineol in mandarin oils has been determined using a fully-automated, multidimensional, double-oven GC-GC system. This system allows fractions to be multitransferred during the same GC analysis and the use of the two GCs independently when the multitransfer option is not used. The results obtained allowed the characterization of mandarin essential oil and the determination of extraneous oils added to or contaminating the oil.