Silver nanoclusters (Ag NCs) have attracted much research interest because of their unique size-dependent optical, electronic, magnetic, and catalytic properties that bridge the gap between small molecules (e.g. organometallic compounds) and bulk crystals (diameter typically >2 nm). As the size of silver nanoparticles decreases to the Fermi wavelength of an electron, discrete energy levels begin to form, thus interactions with light lead to electronic transitions between different energy levels and strong photoluminescence. Additionally, it has been demonstrated that the unique catalytic activity depends strongly on the size of metal nanoparticles (NPs). Because of the outstanding photoluminescence properties, good biocompatibility and excellent catalytic activity of Ag NCs, this chapter is focused on the recent advances of Ag NCs including the synthesis, structural characterizations, novel physical and chemical properties and potential applications.