We report synthesis and characterization of nanoparticles and thin films of undoped and cerium doped zinc oxide (Ce:ZnO).Samples were prepared by sol–gel and spin coating method. The effect of cerium concentrations, as a rare- earth impurity, on structural and optical properties of ZnO is examined. X-ray diffraction (XRD) measurements have proven that the films are polycrystalline with the (101) as preferential crystallographic orientation. Grain size of the prepared ZnO NPs is approximately 20 nm and for the doped samples is ~43 nm. From the differential thermal analysis crystallization thermal threshold was detected to be 400 °C. As observed by field emission scanning electron microscopy, XRD and optical transmission, the film microstructure is strongly dependent on the dopant concentration. Data obtained from the UV–Visible spectroscopy shows a blue shift in the absorption edge of cerium doped ZnO which is confirmed by optical band gap calculation.