In the present work, polystyrene/zinc oxide (PS/ZnO) nanocomposite films are prepared by simple mixing followed by film deposition, using spin-coating technique. Although there are a few reports on the UV-shielding properties of PS/ZnO nanocomposite films, these reports deal with rather thick films obtained by solution casting. Spin coating is a more advantageous technique where one cart control the film thickness by suitably adjusting the viscosity of the solution and the spinning speed and get homogeneous films with thickness around a few hundreds of nanometers. These aspects provide the motivation for the present work where emphasis is given to investigating the optical properties of PS/ZnO nanocomposite films obtained by spin coating and analyzing the effects of each component of the composite (PS/ZnO) on the properties of the other. The nanocomposite films are found to be highly transparent throughout the visible region and the thermal stability is better compared with PS. The optical absorption of the composite films in the UV region is quite high, and this aspect highlights the prospects of applications of these films in UV shielding. The PS matrix brings about considerable surface modification of ZnO nanoparticles, resulting in the reduction of defect states within ZnO and facilitating sharp, near band edge photoluminescence emission. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120: 1361-1366, 2011