Crack free, and dense ZnAl2O4 thin films have been prepared by a sol-gel method using aluminum sec-butoxide and zinc acetate. The complete single phase cubic structure of ZnAl2O4 was formed on a silicon (100) substrate at an annealing temperature of 700 degreesC for 5 h. As the annealing temperature increased from 700 to 800 degreesC, we did not observe any kind of diffusion of Si in the formation of silicate phase at the interface of Si and ZnAl2O4 phase as observed by grazing angle XRD. Structural, morphological and elemental evolution of these ZnAl2O4 thin films produced by sol-gel synthesis were characterized by grazing incidence X-ray diffraction (GIXRD), tapping mode atomic force microscopy (TMAFM), and X-ray photoelectron spectroscopy (XPS), respectively.