The oxidation of some α-hydroxy acids like glycolic acid (GA), malic acid (MLA), lactic acid (LA) and mandelic acid (MA) by triethylammonium fluorochromate (TriEAFC) have been studied in aqueous acetic acid medium. The oxidation leads to the formation of the corresponding oxo acids. The reaction is first order with respect to TriEAFC, hydroxy acids and [H+] and the reaction is catalyzed by hydrogen ions. The reaction rate increased remarkably with the increase in the proportion of acetic acid in the solvent medium. Various thermodynamic parameters have been determined. A suitable mechanism has been proposed.