Hyperbranched polymers are synthesized via a cobalt(II) mediated emulsion copolymerization of methyl methacrylate and diethylene glycol dimethacrylate. The concentration of divinyl monomer and chain transfer activity have to be balanced in order to prevent gelation of the polymer particles. The physiochemical properties of the cobalt(II) complex, specifically the intrinsic chain transfer activity and the partitioning behavior, play a crucial role in governing the polymer architecture (i.e., branched versus cross-linked). Furthermore, an empirical correlation, based on the chain transfer frequency and the divinyl monomer mol fraction, is presented and validated with the results obtained in emulsion polymerization as well as with available literature data.