A simple method for the firm and effective in situ incorporation of zinc ions in a cross-linked polyurethane (PU) matrix containing isonicotinamide moieties is developed. The PU polymerization takes place in the presence of different concentrations of zinc acetate dihydrate (ZnAc), which acts both as a catalyst and a source of water molecules necessary for the formation of the porogenic agent (CO2). The textural porosity of the material increases with the increase of the initial concentration of ZnAc. The analyses of the as-prepared and/or isothermally annealed samples show a high compatibility between the cross-linked polymer matrix and the zinc ions derived from the ZnAc in all of the prepared hybrid materials. After the calcination the monodispersed and uniform ZnO nanoparticles are formed, indicating a uniform distribution of nucleation sites in the pre-calcinated hybrid materials. The antibacterial activity tests against Escherichia coil demonstrated that the macroporous sample obtained from 70 wt% of ZnAc exhibits extremely strong biocidal properties. (C) 2012 Elsevier Ltd. All rights reserved.