The structure and photoluminescence (PL) of ZnO films deposited on Si (111) substrates by chemical spray deposition using aqueous solution of zinc acetate [Zn (CH3 CO2)2 , 2H2O] was investigated. It was found that these properties depend strongly on growth temperature and grain size. The samples grown at the optimum deposition conditions can generate stronger luminescence. It was revealed by X-ray diffraction that the preferred orientation of poly-crystals is along C-axis, with hexagonal wurtzite structure. PL spectroscopy results shows an evident ultra-violet (UV) emission observed near 380 nm with a broad low intensity band centred at 430 nm. The band was reported as being caused by the defects in the grain boundaries of ZnO. Under optimum deposition conditions a low resistivity and a high optical transmittance of the order of 2.8×10−4 Ω cm and 90%, respectively, were obtained.