A novel visible light mediated catalytic system based on low cost iron complex, that is, Fe(bpy)(3)(PF)(6) photocatalyst that initiates and control the free radical polymerization of methacrylates using ethyl -bromoisobutyrate (EBriB) as an initiator and 20 watt LED as light source is developed. The polymerization is initiated with turning the light on and immediately terminated by turning the light off. In addition, the molecular weight of polymer can be varied by changing the ratio of monomer and initiator. The merits of the present methodology lie in the use of low cost less precious, highly abundant iron-based photocatalyst, avoidance of sacrificial donor and need of lower catalyst amount under visible light. The optimum amount of catalyst and initiator were established and successful polymerization of various methacrylates was achieved under the optimized polymerization conditions. (c) 2015 Wiley Periodicals, Inc.