ZnO-CeO 2 nanostructures were synthesized by simple and efficient low temperature method. The structure and morphology of the ZnO-CeO 2 nanostructures were characterized by X-ray powder diffraction (XRD) and field emission scanning electron microscopy (FESEM), which revealed elongated shaped CeO 2 nanoparticles with diameters of 40–90 nm distributed on the surface of elongated ZnO nanostructures with diameters of 50–200 nm (edge-centre). Further the structure of the synthesized ZnO-CeO 2 nanostructure was supported by Raman spectra and Fourier transform infrared spectroscopy (FTIR). UV-vis absorption spectrum was used to confirm the optical properties of the CeO 2 doped ZnO nanostructures. Photo-catalytic activity of CeO 2 doped ZnO nanostructure was evaluated by degradation of acridine orange and methylene blue which degraded 84.55% and 48.65% in 170 min, respectively. ZnO-CeO 2 nanostructures also showed good sensitivity (0.8331 μA·cm −2 ·(mol/l) −1 ) in short response time (10 s) by applying to chemical sensing using ethanol as a target compound by I – V technique. These degradation and chemical sensing properties of ZnO-CeO 2 nanostructures are of great importance for the application of ZnO-CeO 2 system as a photo-catalyst and chemical sensor.