The development of thins layers with antimicrobial priorities has been a key factor for inhibiting the growth of microorganisms and preventing nosocomial infections. This research work focuses on the synthesis and characterization of thin layers of functional metal oxides based on ZnO nanoparticles for applications to surfaces and coatings on various supports (paints, coatings …). In our work we developped as antibacterial agents, nanoparticles of zinc oxide. The synthesis of nanoparticles is performed with sol-gel method, we obtained nanoparticles around 3 nm of diameter. The antibacterial activity has been studied on strains from the European pharmacopoeia; Staphylococcus aureus (ATCC 6538) and Escherichia Coli (ATCC 8739). The test consists in artificial contamination by inoculum of microorganisms. We developed specific methodology for thin layer antibacterial tests. Results show an inhibition of bacterial growth by reduction greater than 5 log 10 of the initial bacterial population.