Silver nanoparticles have found tremendous applications in the field of diagnostics and therapeutics. This work was aimed to study the antioxidant activity of Ag nanoparticles in water by scavengers the free radicals produced by radiation. The antioxidant properties of silver nanoparticles prepared by wire explosion technique have been evaluated using the 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) assay. Ag nanoparticles were characterized by UV-Visible absorption and the results showed surface Plasmon resonance absorption peaks around 397nm. The nanoparticle average size and its size distribution were determinate by Atomic Force Microscopy (AFM). The results showed that the absorption intensity varying systematically with increasing silver nanoparticles concentration with certain limits. So Ag nanoparticles were found to have significant antioxidant capacity and thus can be used as potential radical scavenger against deleterious damages caused by the free radicals.