Abstract: An antimicrobial substrate is disclosed, having adhered to at least a part of its surface an organosilicon quaternary ammonium salt compound, such as 3-(trimethoxysilyl)propyl-dimethyloctadecyl ammonium chloride for example, and having a cationic, preferably hydrophilic, polymer, such as a polyethylene imine or polyhexamethylene biguanide hydrochloride. A method is further disclosed for producing the substrate, as well as a composition for use in the production of the substrate.