The oils from the umbel rays, stems, leaves, fruits and the whole aerial parts ofBupleurum gibraltariumLam. have been examined by means of GC/MS and retention indices. The dominant constituents in the oil from the whole aerial parts were found to be: α-pinene (5.9%), sabinene (9.2%), limonene (6.5%), 2,3,4-trimethylbenzaldehyde (17.2%), terpinen4-ol (5.1%),trans-chrysanthenyl acetate (4.7%), elemol (4.3%) and guaiol (5.3%). The major components of the umbel rays oil were: α-pinene (17.6%), sabinene (33.8%), limonene (7.3%), and 2,3,4-trimethyl-benzaldehyde (8.4%). The stem oil was characterized by the presence of α-pinene (6.0%), sabinene (21.8%), limonene (7.2%), 2,3,4-trimethylbenzaldehyde (10.7%), guaiol isomer (5.1%), elemol (5.5%) and guaiol (5.4%). The leaf oil had as main components α-pinene (130%), sabinene (50%) and limonene (10.0%), whereas in the oil from the fruits, α-pinene (42.7%), sabinene (28.3%), and limonene (9.0%) were found to be the most important ones