The aim of the present study was to develop a process for the preparation of nanoparticles with antybacterial/bacteriostatic properties including the conditions of using these particles in textile-polymeric coating materials with stable bacteriostatic properties. The developed functional particles consist of submicro-spheres (mainly of SiO 2 - Fig. 1) made by the,,sol-gel" technique. On their developed surface,,,nanoislets" of an antibacterial agent such as metallic silver (Ag) were durably deposited (Figs 2 and 3). Such bioactive particles were then incorporated into either hydrophobic (with micro-porous structure) or hydrophilic (with compact structure) polyurethane coats during their production, obtaining the required uniform dispersion of single functional nanoparticles in the polymeric matrix (Fig. 4). To assess the performance stability of the bacteriostatic coating materials they were subjected to 10 standard laundering tests and no deterioration was found in their bacteriostatic properties, as well as in their structure and characteristics such as barrier and hygienic properties (watertightness, water vapor permeability or resistance of water vapor flow) as compared to those of corresponding unmodified materials (Figs 5, 6, 7, Tables 1 and 2).