A self organizing antimicrobial finish on acrylate-based materials was achieved by adding only 0.4 wt% of a biocidal macromer to the monomer mixture prior polymerization. The materials surface kills the infectious bacterium Staphylococcus aureus without releasing the biocide (Figure, lower section) and stays active even alter 45 d of constant washing. Confocal Raman spectroscopy and fluorescence microscopy (Figure, upper section) reveal that the biocide has migrated to the surface of the materials during polymerization.