Polymers containing o-nitrobenzyl esters are promising for preparation of light sensitive materials. o-Nitrobenzyl methacrylate has already been polymerized by controlled ATRP or RAFT. Unfortunately, the radical polymerization of o-nitrobenzyl acrylate (NBA) was not controlled until now due to inhibition and retardation effects coming from the nitro-aromatic groups. Recent developments in the Single Electron Transfer-Living Radical Polymerization (SET-LRP) provide us an access to control this NBA polymerization and living character of this NBA SET-LRP is demonstrated. Effects of CuBr2 and ligand concentrations, as well as Cu(0) wire length on SET-LRP kinetics are shown presently. A first-order kinetics with respect to the NBA concentration is observed after one induction period. SET-LRP proceeds with a linear evolution of molecular weight and a narrow distribution. High initiation efficiency close to 1 and high chain-end functionality (similar to 93%) are reached. Chain extension of poly(o-nitrobenzyl acrylate) is realized with methyl acrylate (MA) to obtain well defined poly(o-nitrobenzyl acrylate)-b-poly(methyl acrylate) (PNBA-b-PMA). Finally, light-sensitive properties of PNBA are checked upon UV irradiation. (C) 2014 Wiley Periodicals, Inc.