This chapter reviews surface-initiated living radical polymerizations via iodine transfer polymerization (ITP), organotellurium-mediated radical polymerization (TERP), and reversible chain-transfer catalyzed polymerization (RTCP) using organic catalysts. The successful application of these polymerizations made it possible to graft various polymers with well-defined structures onto flat substrates and nanoparticles. Living radical polymerizations, including ITP, TERP, and RTCP, also lead to a striking increase in the graft density. Because of their unique advantages as synthetic tools, ITP, TERP, and RTCP can be used to expand the scope of controlled surface modification.