Silver nanoparticles (AgNPs) with mean diameter of 150 nm were synthesized by using an aqueous-basedreduction method. Ascorbic acid and sodium hydroxide (NaOH) were used as a reducing agent and as acatalyst, respectively. These AgNPs were subsequently coated with a layer of TiO2 to form Ag/TiO2 core-shellnanoparticles by using a sol-gel method. The particle sizes and morphology of Ag/TiO2 core-shellnanoparticles were characterized using scanning electron microscopy (SEM) and transition electronmicroscopy (TEM). The photocatalytic activity of the Ag/TiO2 core-shell nanoparticles were evaluated basedon the degradation of methylene blue (MB) as the model reaction. The TiO2 coating has resulted in theenhanced photocatalytic activity of Ag nanoparticles as compared to bare Ag nanoparticles.