Zn0.95-xMg0.05AlxO solutions with different (x = 0.0, 0.01, 0.02, 0.05, and 0.1) compositions were synthesized by the sol-gel technique using Zn, Mg and Al based alkoxide. The effects of doping ratio and annealing temperature on the structure and magnetic properties were investigated systematically. The phase and the crystal structure of the Zn0.95-xMg0.05AlxO nanoparticles were characterized using X-Ray diffraction. The size and microstructure of samples were characterized by Scanning Electron Microscope and X-Ray diffraction. The particle sizes of nanoparticles were observed in the 20-25 nm range. ESR spectra of Zn0.95-xMg0.05AlxO powder samples were collected at room temperature on a Bruker EMX model X-band spectrometer operating at a frequency of 9.50 GHz. (C) 2013 Elsevier Ltd. All rights reserved.