In this work, living radical polymerizations of a water-soluble monomer poly(ethylene glycol) monomethyl ether methacylate (PEGMA) in bulk with low-toxic iron catalyst system, including iron chloride hexahydrate and triphenylphosphine, were carried out successfully. Effect of reaction temperature and catalyst concentration on the polymerization of PEGMA was investigated. The polymerization kinetics showed the features of "living''/controlled radical polymerization. For example, M-n,M-GPC values of the resultant polymers increased linearly with monomer conversion. A faster polymerization of PEGMA could be obtained in the presence of a reducing agent Fe(0) wire or ascorbic acid. In the case of Fe(0) wire as the reducing agent, a monomer conversion of 80% was obtained in 80 min of reaction time at 90 degrees C, yielding a water-soluble poly(PEGMA) with M-n = 65,500 g mol(-1) and M-w/M-n = 1.39. The features of "living''/controlled radical polymerization of PEGMA were verified by analysis of chain-end and chain-extension experiments. (C) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 50: 2194-2200, 2012