Antiviral activity of metallic Ag nanoparticles immobilized on textile fabricswere investigated. The Ag nanoparticles synthesized by radiochemical process arefirmly immobilized on the surface of support textile fabrics of cotton. Small Agparticles of about 2–4 nm were observed together with relativelylarge particles of more than 10 nm. The Ag nanoparticles showed antiviralactivity against Influenza A and Feline Calicivirus. The antiviral activitysignificantly depended on the concentration of the Eagle’s minimalessential medium. It was implied that the surface passivation by inhibitoryagent lead to the deactivation of metallic Ag nanoparticles.