The polar solvents, N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), and acetonitrile (CH3CN) were used as ligands for iron(III)-mediated activators generated by electron transfer atom transfer radical polymerizations (AGET ATRPs) of methyl methacrylate (MMA) with various initiators and reducing agents. Polymerizations were conducted with a molar ratio of [MMA](0)/[initiator](0)/[FeBr3](0)/[reducing agent](0)=100:1:1:0.5 and a volume ratio of MMA/solvent=2:1 at 60 degrees C to investigate the effects of initiator, solvent and reducing agent, and most of the systems showed the typical features of living/controlled radical polymerization. In order to get a deeper understanding of the mechanism, the amount of the reducing agent was changed to study the polymerization behavior. (c) 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1020-1027