Reverse atom transfer radical polymerization (RATRP) of methyl methacrylate (MMA) with azobisisobutyronitrile (AIBN)/FeCl3/lactic acid as initiating system was successfully carried out in N,N-dimethylformamide (DMF) for the first time. Kinetics as well as molecular weight distribution data indicated towards the controlled nature of polymerization. The polymerization not only showed the best control of molecular weight and its distribution but also provided a rather rapid reaction rate with the molar ratio of [MMA]:[AIBN]:[FeCl3]:[lactic acid] = 300 : 1 : 1 : 2. The polymerization rate increased with increasing the polymerization temperature. The apparent activation energy was calculated to be 47.90 kJ/mol. The rate of polymerization in DMF was faster than that in acetonitrile, cyclohexanone, toluene, and xylene. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114: 1593-1597, 2009