Ag nanoparticles were added to low.-d. polyethylene (0.2-1.0% by mass) to improve its biocide activity. The nanocomposite was homogenized by extrusion, processed to test samples by injection molding and studied for mech. strength, rheolog. properties, H2O vapor permeability and biocidic action against Escherichia coli, Bacillus subtilis and Candida albicans. The addn. of Ag nanoparticles resulted in increasing the tensile strength, Young modulus, permeability and melt flow index but did not increase the biocide activity except for Escherichia coli for the Ag content 0.4-0.6% by mass.