Quaternary ammonium or phosphonium salts, immobilized on polymeric support, were obtained by polymer-analogous reactions on ＇gel-type＇ styrene-divinylbenzene copolymers and by trans-quaternization of the ammonium groups to phosphonium groups. Polymeric catalysts with degrees of functionalization of 0.15-2.78 mmole g(-1) were used in the oxidation of benzyl alcohol with hydrogen peroxide. The activity of the single -onium salts increases as a consequence of association of ammonium and phosphonium salts on the polymeric support. The activity of polymer-supported ammonium and phosphonium salts increases with the number of carbon atoms contained in the alkyl radicals of the -onium and of the functionalization degree with phosphonium groups. Addition of RuCl3 . 3H(2)O to the reaction media increases the activity of the phase-transfer catalysts.