Poly(hydroxyethyl methacrylate)/silica (PHEMA/SiO(2)) hybrid organic-inorganic nanocomposites were prepared through the simultaneous polymerization of 2-hydroxyethyl methacrylate and tetraethoxysilane. PHEMA/SiO(2) materials were obtained as monolithic and transparent films consisting of silica nanoparticles (diameter below 100 nm) surrounded by the PHEMA matrix. The films were crushed into fine powder and the PHEMA/SiO(2) particles were used as filler of methacrylate monomers. The polymeric methacrylate present in the PHEMA/SiO(2) hybrid particles improves the compatibility of the filler with the methacrylate monomer to be photopolymerized, resulting in enhanced wetting capabilities. The composites prepared from PHEMA/SiO(2)-prepolymerized particles offer the possibility of reduced polymerization shrinkage without severe reductions in flow characteristics of the precured polymers. The monomer conversions of composites prepared with either 30 or 60 wt% PHEMA/SiO(2) particles were similar. This indicates that the penetration of visible radiation into the sample is not reduced significantly by the presence of the filler.