Organic-inorganic hybrid materials were prepared by a convenient two-step curing procedure based on sol-gel condensation and subsequent photopolymerization. Novel bismethacrylate-based hybrid monomers with pendant, condensable alkoxysilane groups were prepared by Michael addition and possessed number-average molecular weights between 580 and 1600 g/mol. The formation of inorganic networks by sol- gel condensation of the alkoxysilane groups in the presence of aqueous methacrylic acid was monitored with rheological measurements. The condensation conversion was monitored with solid-state Si-29 cross-polarization/magic-angle spinning NMR spectroscopy. Subsequent photopolymerization led to organic-inorganic hybrid networks and low volume shrinkage, ranging from 4.2 to 8.3%, depending on the molecular weight of the hybrid monomer applied. Highly filled composite materials with glass filler fractions greater than 75% showed attractive mechanical properties with Young's moduli of 2700-6200 MPa.