Synthesis of ZnO microprisms was achieved on Si substrates coated with Ce(NO3)3 thin films by a simple carbon-thermal evaporation method. The pre-deposited Ce(NO3)3 films may decompose at about 200 °C to be CeO2 microparticles, which can provide growing sites for the ZnO microstructures. The structural and optical properties of the as-obtained ZnO microstructures were characterized by a number of techniques, including X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, Fourier transform infrared spectrum and photoluminescence. The results indicate that the as-prepared ZnO microprisms exhibit hexagonal prism-like platforms showing well-defined crystallographic facets and hexagonal pyramid-like tops. Room temperature photoluminescence spectrum of the microstructures shows a strong ultraviolet emission band accompanied by a broad weak green emission band. Finally, the growth mechanism was discussed based on the experimental conditions and the ZnO crystal growth habits.