In order to obtain nano fiber mats which posesses antibacterial properties, we studied the electrospinnability of PVA solutions. Due to less toxiccity of ZnO to humans than silver, they are attractive as antibacterial agents in biomedical applications. First the effect of the nanoparticles on the solution viscosity of PVA solutions, especially we focused on the effect of the particle size and the nanoparticle volume fraction on the viscosity of the suspension. We found that the unusual increase of the solution viscosity of the suspensions as increasing the volume fraction of the nanoparticles and decreasing the size of the particles despite of very low volume fraction of 0.02%. The measured viscosities at the volume fraction of the nanoparticles are significantly higher than those predicted by the Einstein’s equation. The increased viscosities affected the electrospinability of PVA/ZnO suspensions. We will also present the influence of the size of ZnO nanoparticles on their antibacterial action against strains of three bacteria: one Gram-negative, Escherichia coli and two Gram-positive, Bacillus subtilis and Staphylococcus aureus.