We report a novel strategy for incorporation of titanium dioxide (TiO2) particles into poly(methyl methacrylate) (PMMA) to exploit high refractive and transparent organic-inorganic hybrid materials. Formation of TiO2 particles of around 20 nm was conducted within hydrophilic core of block copolymer micelles of poly(methyl methacrylate-block-acrylic acid) (PMMA-b-PAA) in toluene via sol-gel process from titanium isopropoxide and hydrochloric acid. Subsequently, incorporation of TiO2 particles into PMMA matrix was carried out by casting toluene solution of TiO2 precursor-loaded copolymer micelles, prepared from PMMA(350)-b-PAA(93) and the precursor of mole ratio Ti4+/carboxyl 4.0, and PMMA. Hybrid films of TiO2/PMMA exhibited high transparency to achieve transmission over 87% at 500 nm at 30 wt % of TiO2 content. The refractive index of resulting hybrid films at 633 nm linearly increased with TiO2 content to attain 1.579 at 30 wt % TiO2, which was 0.1 higher than that of PMMA. Cross-sectional transmission electron microscope images of TiO2/PMMA hybrid films showed existence of TiO2 clusters less than 100 nm, which were probably formed by aggregation or agglutination of TiO2 particles during a drying process. It was also observed that decomposition temperature of the hybrid films elevated with increasing TiO2 content. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 712-718, 2011