The subject of the present invention is a method for separating a carboxylic acid in salified form bearing at least one halogen atom at the α position of the carbonyl group from a medium comprising it. The method according to the invention, for separating a carboxylic acid in salified form bearing at least one halogen atom at the α position of the carbonyl group from an aqueous medium comprising it, is characterized by the fact that the latter is brought into contact with an onium salt leading to the formation of two phases: an organic phase comprising the salt resulting from the reaction of the salt of the carboxylic acid bearing at least one halogen atom at the α position of the carbonyl group and of the onium salt leading to the displacement of the cation from the carboxylic acid by the onium, an aqueous phase comprising the various salts, in particular the one resulting from the reaction of the cation of the carboxylic acid with the anion of the onium, and by the fact that the organic and aqueous phases are then separated and that the onium salt of the carboxylic acid is recovered from the organic phase.