Abstract Essential oil comparison of flowers from Hypericum perforatum L. subsp. perforatum and subsp. veronense (Schrank) Ces. from central Italy, performed by GC and GC/MS, led us to identify two chemotypes within H. perforatum taxon. α-Pinene and 2,6-dimethyloctane were the most abundant components in H. perforatum subsp. veronense flower oil, while β-caryophyllene and 2,6-dimethylheptane were predominant in the oil of H. perforatum subsp. perforatum. Monoterpenes hydrocarbons were also predominant in the oil of subsp. veronense, while sesquiterpenes and aliphatic hydrocarbons were found in the oil of subsp. perforatum. Such quantitative differentiation in the oil composition of the flowers may be useful as a chemotaxonomic intraspecific discriminatory character. Key Word Index: Hypericum perforatum subsp. perforatum Hypericum perforatum subsp. veronense Hypericaceaeessential oil compositionα-pinene2,6-dimethyloctaneβ-caryophyllene2,6-dimethylheptane