Abstract Uncoated ZnS, ZnS:Mn2+, CdS and different thickness of CdS coated ZnS:Mn2+ core–shell nanoparticles were successfully synthesized by a simple chemical method in an air atmosphere. X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques were used to characterize the uncoated and the novel ZnS:Mn2+/CdS core–shell nanoparticles. The results show that the size of the ZnS:Mn2+/CdS core–shell nanoparticles is less than the bare ZnS:Mn2+. The PL study of ZnS:Mn2+/CdS core–shell nanoparticles shows an enhanced intensity than ZnS:Mn2+. The coating of CdS layer over ZnS:Mn2+ tuned the PL emission in the visible region. Addition of cadmium acetate (Cd 4 and 5M) in ZnS:Mn2+ shows a distinct PL peak centered at 542nm. The presence of Mn2+ ions in ZnS lattice and the growth of the CdS on ZnS:Mn2+ nanoparticles were confirmed by the ESR spectra.