A systematic study on the synthesis and antibacterial activity of the quaternary “onium” salts grafted on an insoluble “gel-type” styrene-7% divinylbenzene copolymer by polymer-analogous reactions is showed. Antibacterial activity of quaternary ammonium and/or phosphonium salts grafted on polymer-supports has been studied against Staphylococcus aureus and Escherichia coli. A wide variety of “onium” salts bound to macromolecular supports with different quaternary groups and different quaternary chain length substituents were examined. The antibacterial activity of mixed “onium” salts increases as a consequence of the association of ammonium and phosphonium salts grafted on the same polymeric support. A systematic study on the synthesis and antibacterial activity of the quaternary “onium ” salts grafted on an insoluble “gel-type ” styrene-7% divinylbenzene copolymer by polymer-analogous reactions was showed. Antibacterial activity of quaternary ammonium and / or phosphonium salts grafted on polymer-supports has been studied against Staphylococcus aureus and Escherichia coli. A wide variety of “onium ” salts bound to macromolecular supports with different quaternary groups and different quaternary chain length substituents were examined. The antibacterial activity of mixed “onium ” salts increases as a consequence of the association of ammonium and phosphonium salts grafted on the same polymeric support.