Syzygium aromaticum essential oil is widely used in dental care, as an antiseptic and analgesic and is effective against a large number of bacteria. The major component of clove essential oils is usually considered to be eugenol, with ?-caryophyllene and eugenyl acetate, being present although in lower concentrations. A review of published results reveals a great variability in the chemical composition of clove essential oils. The purpose of this study is to compare the chemical composition of Madagascar, Indonesia and Zanzibar bud, leaf and stem essential oils. 121 commercial essential oils isolated from bud, leaf and stem were used in this work. The oils were analyzed by GC and ten constituents were identified from the whole. The major constituent of Madagascar and Indonesia bud essential oils was eugenol (72.08 - 80.71% and 77.32 - 82.36% respectively). Out of this constituent which was common to Madagascar and Indonesia bud essential oils, significant difference was observed with respect to eugenyl acetate (11.68 - 21.32% vs 8.61 - 10.55% respectively) and ?-caryophyllene (2.76 - 6.38% vs 5.34 - 8.64% respectively). Comparing chemical composition of leaf essential oils from Madagascar with those of Indonesia, variation in the contents of main constituent, eugenol (80.87 - 83.58% vs 75.04 - 77.54%), ?-caryophyllene (11.65 - 15.02 vs 17.04 - 19.53%) and eugenyl acetate (0.29 - 1.45% vs 0 - 0.06%) was observed. The major constituents of Madagascar, Indonesia and Zanzibar stem essential oils were eugenol (91.81 - 96.65%, 88.76 - 89.28% and 87.52 - 89.47%, respectively) and ?-caryophyllene (1.66 - 4.48%, 7.40 - 7.75% and 7.19 - 9.70%). For each plant material, variation in the percentage of the main constituents was observed according to the sample geographic origin.