The preparation of hybrid organic/inorganic nanocomposites comprised of well-defined polymers was reviewed. In particular, synthetic methods using controlled/"living" radical polymerization techniques, such as stable free-radical/nitroxide-mediated polymerizations, atom transfer radical polymerization, and reversible addition-fragmentation chain-transfer polymerization were described. The various approaches taken to prepare hybrid copolymers, nanoparticles, polymer brushes, dispersed silicate nanocomposites, and nanoporous materials were discussed.