The invention relates to a method for the extraction of all unsaponifiable fraction contained in a vegetable oil, an oil originating from a micro-organism or a vegetable butter or in a co-product from the vegetable oil refining industry, such as deodorization discharge. The method includes at least: A) a step comprising the transformation of the aforementioned oils, butter or co-product from the vegetable oil refining industry or oils originating from micro-organisms into a hydro-alcoholic solution by means of, in particular, a step selected from saponification and esterification steps; B) a step comprising the extraction of the hydro-alcoholic solution in which the fatty fraction is separated from the unsaponifiable fraction by means of liquid/liquid extraction; and C) an optional step comprising the purification of the unsaponifiable fraction, selected from the group containing crystallization and liquid/liquid extraction steps. According to the invention, at least one step from the liquid/liquid extraction steps in step B, the crystallization steps in step C and the liquid/liquid extraction steps in step C is performed using a first solvent system containing a concentration of solvent selected from among: fluorinated aromatic solvents, particularly trifluorotoluene (BTF) and hexafluorobenzene (BHF); tert-butyl ethers, particularly 2-ethoxy-2-methylpropane, also known as ethyl-tert-butyl-ether (ETBE); solvents comprising at least one silicon atom, particularly hexamethyldisiloxane (HMDS) and tetramethylsilane (TMS); methyl-tetrahydrofuran (MeTHF); and mixtures thereof, representing at least 50 vol.-% in relation to the total volume of the solvent system. The invention also relates to the fractions obtained using this method and to compositions containing said fractions.