Silver (Ag)-doped (0, 5, 10 and 15%) ZnS nanoparticles are synthesized by microwave-assisted chemical route using polyvinylpyrrolidone (PVP). We study the compositional, structural, optical and luminescence properties by energy-dispersive analysis of X-rays (EDAX), transmission electron microscopy (TEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), UV–Vis spectroscopy and photoluminescence (PL) spectroscopy, respectively. Synthesized Ag-doped ZnS nanoparticles do not possess any impurity as seen from EDAX spectra. TEM images show particles to be in spherical shape with agglomeration, and corresponding selected area electron diffraction (SAED) pattern showed that they are polycrystalline in nature. Allowed LO and TO modes corresponding to cubic phase for all the samples are observed in Raman spectra. FTIR spectroscopy is used to study the interaction between PVP and as-synthesized nanoparticles. Blue shift can be seen in pure and Ag-doped ZnS nanoparticles compared to bulk ZnS as seen from absorption spectra. Green emission is observed in PL spectra due to Ag doping without showing any quenching behavior.