In the present work, we have studied the effect of ZnCl₂ dopant on the optical properties of (polymethyl methacrylate) (PMMA) polymer. Pure and ZnCl₂ doped PMMA films were prepared using solvent casting method. Optical energy band gap E_g was estimated by using UV-VI-NIR spectra and it was classified as an indirect allowed transition. In general, E_g was found to decrease with the increasing of dopant concentration. The refractive indices of the samples were measured and it was found to increase with the increasing of dopant concentration. Optical transmittance, reflectance and extinction coefficient were also investigated and correlated with the action of doping process.