The electrochemical intercalation of oxygen into La2CuO4 has been studied in various anhydrous organic media. Several combinations between an organic solvent and a supporting electrolyte have been examined. The addition of an oxygen source such as KO2 or H2O has been found to be unnecessary. Experiments have shown that the electrochemical oxygen insertion mainly implies the decomposition of the solvent leading to the formation of oxygen species able to oxidize the starting material. La2CuO4.10 has been prepared in the DMSO associated with nBu(4)NClO(4). A superconducting behavior is observed below 44 K and the physical characterizations of the material before and after controlled anodic polarization are reported. It has also been shown that this intercalation reaction is reversible. The mechanism of the oxygen intercalation is tentatively proposed with respect to the organic media. Fluorine has also been intercalated for the first time in such media. (C) 2004 The Electrochemical Society.