Zinc sulfide (ZnS) nanocrystals (NCs) doped with transition metal ions (Ag+) (ZnS:Ag+) were synthesized by a low temperature co-precipitation method using thioglycerol as a capping agent. The X-ray photoelectron spectroscopy (XPS) study suggested that Ag dopant was successfully doped into the ZnS:Ag+NCs matrices. The zinc blende structure of the ZnS:Ag+NCs was confirmed by X-ray diffraction (XRD) analysis. The UV/Vis absorbance spectra for all of the synthesized NCs showed a gradual red shift while Ag(+)ions concentrations were increased. Photoluminescence (PL) peak for un-doped ZnS NCs exhibited at 465nm. On the other hand, doping of Ag(+)ions into ZnS NCs in the presence of thioglycerol resulted in PL peaks shifted towards red shift in accordance with the increasing Ag(+)ions concentration.