Poly(oxyethylene)-dicarboxylic acids were obtained in high yields by room temperature oxidation of poly(ethylene glycol)s of molecular weights in the 4000 -100,000 range using Jone's reagent (CrO 3 and H 2 SO 4 ) as the oxidizing agent. Oxidation by-products from the reaction mixture were eliminated by adsorbing chromium salts onto activated charcoal. The acid values of poly(oxyethylene)-dicarboxylic acids so synthesized were in agreement with the theoretical values. Poly(oxyethylene)-dicarboxylic acids were characterized by 1 H-NMR, IR spectroscopy. Spectral data were in agreement with the proposed structures of products. In summary, a convenient, one pot method for the synthesis of a wide range of poly(oxyethylene)-dicarboxylic acids was developed.