Mn2+-doped ZnS nanoparticles embedded in a silica matrix were prepared by the sol-gel technique. Zinc sulfide nanoparticles were found to be well dispersed as single entities in the silica matrix. An electron spin resonance study indicated magnetically dilute discrete Mn2+ levels rather than Mn clusters, even at higher doping concentration (5 mol.%), probably due to the presence of the SiO2 matrix. Photoluminescence spectra showed characteristic yellow-orange luminescence due to the T-4(1) --> (6)A(1) transition of Mn. The emission energy was blue-shifted for higher doping concentrations.