Polyvinylpyridinium salts were immobilized onto a clay matrix and were then tested for their antibacterial properties. The clay-polyvinylpyridinium matrix was prepared by the copolymerization of gamma-methacryloxypropyltriethoxy silane bonded covalently to clay and 4-vinylpyridine and subsequent quaternization with benzyl halides. Suspension tests for antibacterial properties of the immobilized bactericide against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa demonstrated the high activity of the pyridinium salts that are bonded to the polyacrylate spacer. Advantageously, these insoluble clay-polymer bactericides could be applied without any contamination by the substrate.