We report a one-pot synthesis of silver nanoparticle-polymer composites (Ag-PNCs) in water by a novel finding involving the polycondensation of methoxybenzyl chlorides (MeO-BzCl) directly on Ag nanoparticle surfaces at room temperature, leading to highly soluble antimicrobial nanocomposites. The composites, which are soluble in a range of organic solvents, precipitate in the reaction vessel, making their separation simple. Solutions of the composites can be casted directly on substrates or made into freestanding films. The material was found to be stable for nearly 2 years. A range of substrates have been shown to become antibacterial by direct application of this material. The experiments were conducted with Ag-PNC-loaded filter paper strips and glass substrates. The samples were found to be antimicrobial (against Escerichia coli and Aspergillus niger). The simple one-pot approach of this kind to make organic-soluble antibacterial coatings could have wide implications. © 2009 American Chemical Society.