ZnO thin films were deposited by successive ionic layer adsorption and reaction (SILAR) method using a zinc nitrate and ammonium bath on glass substrates. The number of employed cycles were 50, 100 and 200. The films were studied by X-ray diffraction (XRD), optical absorption (UV–Vis) and μ-Raman. Structural analysis by XRD shows that the as-deposited ZnO films have high-orientation along c-direction (0 0 2). The band gap energy decreases from 3.39 to 3.32 eV with number of cycles. By μ-Raman spectroscopy, the principal vibration modes around 435, 550, 579, and 1100cm-1 were determined.