Doping is an important tool for the modification of physicochemical properties of metal oxide nanoparticles. The present study is devoted to doping Zn 2? in MgO nanoparticles. Substituted brucite precursors, synthesized via sol-gel method, were calcined at 500-1000°C to get the Zn 2? -doped MgO nanoparticles. Phase analysis on the Zn 2? -doped MgO samples using X-ray diffraction showed single set of peaks in the XRD patterns due to cubic MgO. Small nanoparticles (25-55 nm) were observed in the Zn 2? -doped MgO samples by scanning electron microscopy and transmission electron microscopy studies. Optical properties of the Zn 2? -doped MgO nanoparticles were investigated using UV-visible diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) spectroscopy, and absorption near 260 nm and emission bands attributed to defects were observed in the DRS and PL spectra, respectively. Graphical Abstract Zn 2? -doped MgO nanoparticles have been synthesized using Zn 2? -substituted brucite samples as the precursors for the first time. The precursors were prepared by sol-gel method, and the use of such substituted brucite precursors leads to Zn X Mg 1-X O solid solutions with good homogeneity. Studies on optical properties by diffuse reflectance spectroscopy and photoluminescence spectroscopy indicate that the Zn 2? -doped MgO nanoparticles possess interesting optical properties.