Isolation of the volatile concentrate from dried leaves of Seseli bocconi Guss. subsp. praecox Gamisans were obtained by supercritical fluid extraction (SFE) with carbon dioxide. Leaves from different zones of Sardinia (Italy) were collected and treated. Compositions of samples were analyzed by GC-MS. The volatile concentrate of S. bocconi from Buggerru was found to contain: himachalol (16.4%), sabinene (14.8%), beta-phellandrene (8.1%), cis-sabinene hydrate (4.5%). beta-Phellandrene (29.2%), undecane (9.6%), alpha-pinene (6.1%) and beta-guaiene (5.7%) were the main constituents of the volatile extract of S. bocconi from Carloforte. The volatile concentrate of S. bocconi of Ogliastra inland, was composed chiefly by alpha-humulene (17.7%), gamma-himachalene (9.3%), beta-phellandrene (8.0) and bicyclogermacrene (7.7%). The yields of extraction were in the range (0.13-0.60%). A comparison with the hydrodistilled oil revealed in each case a remarkable difference in composition.