Silver nanocluster-silica composite coatings have been deposited by radio frequency (RF) co-sputtering on silica substrates. W-visible absorption and X-ray diffraction spectra of the as deposited and heated samples revealed metal silver nanoclusters of different size, depending on the annealing treatment The. antibacterial activity of several as deposited and annealed samples has been verified in accordance to National Committee for Clinical Laboratory Standards (NCCLS). The antibacterial activity of these coatings was detected up to 450 degrees C. (C) 2009 Elsevier B.V. All rights reserved.