The leaf essential oils of seven Vietnamese species of the genus Cinnamomum were analyzed by gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC/MS). The results showed that the species fall into three groups in which one group contains aromatic components, while the second group contains both terpenes and aromatic constituents and the third group contains only terpene constituents. The first group had only Cinnamomum curvifolium as its member and produced oil rich in benzyl cinnamate and benzyl benzoate. The second group producing mixture of phenylpropanoids and oxygenated monoterpene components includes leaves of Cinnamomum kunstleri (methyl eugenol, terpinen-4-ol and 1,8-cineole) and Cinnamomum mairei (eugenol, 1, 8-cineole, neryl acetate and eugenol acetate). The third group rich in terpene constituents could also be divided into two classes. The first class produced oils rich in monoterpene components and includes Cinnamomum damhaensis (linalool, α-pinene, β-pinene and 1,8-cineole), Cinnamomum cambodianum (linalool and terpinen-4-ol) and Cinnamomum caryophyllus (1,8-cineole, α-pinene and camphene). The second class contains oil with abundance of sesquiterpene compounds and peculiar to Cinnamomum rigidifolium (α-selinene, β-caryophyllene and α-copaene). This paper discusses further the chemotaxonomic importance of these results and previous data on essential oils of Cinnamomum species analysed from Vietnam.