2-Phenyl-2-[(2,2,6,6-tetramethylpiperidino)oxy] ethyl 2-bromopropanoate was successfully used as an initiator in consecutive living radical polymerization routes, such as metal-catalyzed living radical polymerization and nitroxide-mediated free-radical polymerization, to produce various types of acrylonitrile-containing polymers, such as styrene-acrylonitrile, polystyrene-b-styrene-acrylonitrile, polystyreneb-poly(n-butyl acrylate)-b-polyacrylonitrile, and polystyrene-b-polyacrylonitrile. The kinetic data were obtained for the metal-catalyzed living radical polymerization of styrene-acrylonitrile. All the obtained polymers were characterized with H-1 NMR, gel permeation chromatography, and differential scanning calorimetry.