The composition of the twig, xylem and cortex resin oils of Pinus halepensis Miller, P. brutia Tenore and P. canariensis Sweet species grown in natural habitats in Attiki, Greece were analyzed by GC and GC/MS. Thirty five components were detected, characterized and quantified on the basis of their retention indices and mass spectra. The majority of the components were found to be monoterpenes and sesquiterpenes. P. halepensis twig oil was found to be rich in α-pinene (15.8%), δ-3-carene (15.6%), limonene (10.2%) and β-caryophyllene (18.1%). The twig oil of P. brutia contained α-pinene (17.8%), β-pinene (25.5%), δ-3-carene (16.2%) and β-caryophyllene (12.1%), while P. canariensis twig oil contained α-pinene (43.7%), germacrene D (11.0%) and aristolene (12.5%). The cortex resin and xylem oils were all rich in monoterpene hydrocarbons
