Wood of Santalum album and resin of Boswellia carterii Birdw. were used to obtain their volatile oils by means of supercritical fluid extraction with carbon dioxide. Different extraction conditions were tested: 90 bar, 45 °C; 120 bar, 60 °C; and 120 bar, 45 °C. On both matrices, a good process performance was obtained working at 120 bar and 45 °C (density of CO2 = 0.658 g cm−3 ) in the extraction vessel, at 20 bar and 15 °C in the separator and at CO2 flow of 1.5 kg/h. At these conditions the higher yields were obtained: 1.9% for S. album and 6.5% for B. carterii. The main compounds contained in the sandalwood volatile oil were: α-santalol (46.1%), β -santalol (20.4%), epi-β -santalol (6.8%) and trans-α-bergamotol (5.4%). In the corresponding HD essential oil the α-santalol and β -santalol contents were lower: 35.0% and 14.0%, respectively. The volatile oil of B. carterii were made up of incensole acetate (32.0%), octanol acetate (25.1%), incensole (17.8%) and phyllocladene (7.7%). The percentage of the main constituents in the oil obtained by HD was quite different. It contained larger amounts of octanol acetate (45.2%) and phyllocladene (13.2%) and lower amounts of incesole (6.1%) and incensole acetate (13.0%).