In this work, the composition and the proportions of fatty acids in selected oilseeds growing in Turkey were determined. The dried and crushed samples were extracted in a standard Soxhlet extractor with acetone. During supercritical fluid extraction (SFE) the samples were carried out in a 100 mL cylindrical autoclave for 60 min at 515 K and 6.6 MPa at above critical temperature and critical pressure of acetone. After saponification, acidulation, and methylation procedures, methyl esters of the fatty acids from the Soxhlet and SFE were analyzed by a Hewlett-Packard 5790 GC on a 12 m 0.2 mm capillary column coated with Carbowax PEG 20. While the yield of saturated fatty acids from SFE of the samples increased, the yield of linoleic acid decreased. The increases and decreases in the fatty acids were irregular.