Abstract The oil-poor Hypericum perforatum plants were collected at full flowering from ten wild habitats in Lithuania. The essential oils obtained by hydrodistillation were analyzed by GC and GC/MS. The most predominant compound was germacrene D (12.0â29.5%). The second major constituents were β-caryophyllene (8.8â10.5%, three oils), caryophyllene oxide (11.9â13.1%, two samples), β-eudesma-4(15),5-dien-1-ol (9.1â11.7 %, two oils), β-farnesene (9.0%, one sample) and tetradecanal (9.4%) with tetradecanol (9.4%, one oil). The oils were rich in sesquiterpene hydrocarbons (31.8â52.4%). Thirty-one out of the eighty identified constituents were found in the all oils. The identified compounds comprised 87.5â95.6% of the oils. Key Word Index: Hypericum perforatum Hypericaceaeessential oil compositiongermacrene Dβ-caryophyllenecaryophyllene oxideβ-eudesma-4(15),5-dien-1-ol