Zinc Oxide (ZnO) films were prepared on unheated glass substrate by radio frequency (RF) magnetron sputtering technique and post deposition annealing of the ZnO thin film were performed at 350, 400, 450 and 500°C. Post annealing temperature was found to improve the structural and electrical characteristics of the deposited films. The structural properties of the films were carried out by the surface profiler, X-Ray diffraction (XRD), atomic force microscopy (AFM) and field emission scanning electron microscope (FESEM) while the electrical properties were measured using current voltage (I-V) probe measurement system. All samples exhibit the (002) peak and the sample annealed at 500°C gives the highest crystalline quality, highest Rms roughness (1.819 nm) and highest electrical conductivity (3.28 x 10-3 Sm-1).