We report here a sol-gel method to synthesize undoped and Cu doped ZnO nanoparticles. The nanoparticles were characterized using X-ray diffraction technique to understand the crystallographic properties. The results indicate the formation of pure and Cu doped ZnO nanoparticles. The growth was found to be anisotropic. The low concentration of Cu doping does not influence the particles size of ZnO. We have successfully synthesized undoped and Cu doped ZnO nanoparticles using a simple and cost effective sol-gel method. The synthesized nanoparticles exhibit high crystallinity and Cu doping was further confirmed from X-ray diffraction. The diffraction pattern also suggests that the growth of hexagonal ZnO is anisotropic. However due to this low percentage of Cu doping, no significant change in particle size was observed. In this paper, we report a very simple and cost effective sol-gel method to synthesize ZnO nanoparticles followed by typical structural characterization.