Reversible addition fragmentation chain transfer (RAFT) polymerization was used for the first time to produce poly(methyl methacrylate) hyperbranched polymers via the one-pot copolymerization of methyl methacrylate (MMA) and ethylene glycol dimethacrylate, mediated by 2-(2-cyanopropyl) dithiobenzoate. Hyperbranched structures were characterized by H-1 NMR spectroscopy, size exclusion chromatography (SEC), and thermal analyses. Monomer conversions and molecular weight distributions of hyperbranched poly(methyl methacrylate) (PMMA) prepared via RAFT polymerization are much higher and much lower, respectively, than those of the analogous polymers prepared via other living polymerization systems. Furthermore, the living character of the RAFT process was used to polymerize styrene from hyperbranched PMMA precursors (macro chain-transfer agent, macroCTA) and to produce starlike structures with hyperbranched PMMA as the core and polystyrene as the arms. DSC and SEC analyses support the observations made regarding the production of these novel architectures.