Cu/ZnS nanoparticles (grain size about 10 nm, Cu content 1-3%) were co-pptd. from an aq. soln. of Zn(OAc)(2) with CuCl2 in presence of 3-mercaptopropionic acid (MPA) or NH2CH2CH2SH.HCl as stabilizing agents. The nanocrystals prepd. by using MAP contained 1% of Cu and showed the highest blue-green luminescence intensity.