Poly(methylmethacrylate)-silica nanocomposite films were prepared from copolymerizing methylmethacrylate with allylglycidylether-functionalized silica nanoparticles. No alkoxysilane coupling agents and sol–gel reactions were employed in this preparation approach to result in nanocomopsite films having silica contents higher than 70wt%. Good transparency, hardness above 9H grade, and superior surface planarity were observed with the prepared naocomposite films. Glass transition temperatures were not observed with the nanocomposite films by DSC measurement to indicate their good thermal and dimensional stability.