Products with ion-exchange properties have been obtained by heterogeneous sulfonation of polycarbonatemethacrylate (PCM). The resulting polymer and membranes based on it have been studied by means of elemental analysis, titrimetry, and IR spectroscopy. It has been shown that the ion-exchange capacity of the resulting products is 6 mEq/g. Therefore, together with relatively high ionic conductivity and ionexchange capacity, the products hold promise for use as ion-exchange membranes and modified coatings with ion-exchange properties.