The use of plasma-assisted synthesis of effective plasmonic photocatalysts for degradation of aqueous organic pollutants is limited by a lack of understanding of the effects of plasma treatment on the properties of plasmonic nanoparticles. In this study, the effect of cold atmospheric plasma on the optical properties of plasmonic silver (Ag) nanoparticles was investigated. Silver nanoparticles were deposited on quartz surfaces and treated by dielectric barrier discharge plasma for various time. The plasma treated Ag nanoparticles were characterized using UV-visible spectroscopy technique.