In this study, poly(acrylic)/silica hybrid thin films were prepared from various acrylic monomers and monodispersed colloidal silica with a coupling agent MSMA. The silica content in the hybrid thin films was varied from 0 to 50 wt%. The experimental results showed that the coverage area of silica particle by the MSMA decreased with increasing silica content and resulted in the aggregation of silica particle in the hybrid films. Thus, the silica domain in the hybrid films was varied from 20 to 35 nm by the different mole ratios of MSMA to silica. The results of SEM, TEM, and EA supported the above results. The analysis of FTIR and Raman spectra indicated that the degree of photopolymerization was very high. The prepared hybrid films from the crosslinked acrylic polymer moiety showed much better film uniformity, thermal stability and mechanical properties than those obtained from poly(methyl methacrylate). The refractive index decreased linearly with increasing the silica fraction in the hybrid films. Excellent optical transparency was obtained in the prepared hybrid films. These results showed that the prepared hybrid thin films had potential applications as passive films for optical devices.