Atom transfer radical polymerization (ATRP) using activators generated by electron transfer (AGET) was investigated for the controlled polymerization of 2-hydroxyethyl methacrylate (HEMA) in a protic solvent, a 3/2 (v/v) mixture of methyl ethyl ketone and methanol. The AGET process enabled ATRP to be started with an air-stable Cu(II) complex that was reduced in situ by tin(II) 2-ethylhexanoate. The reaction temperature, Cu catalysts with different ligands, and variation of the initial concentration ratio of HEMA to the initiator were examined for the synthesis of well-controlled poly(2-hydroxyethyl methacrylate) and a poly(methyl methacrylate)-b-poly(2-hydroxyethyl methacrylate) block copolymer. The level of control in AGET ATRP was similar to that in normal ATRP in protic solvents, and this resulted in a linear increase in the molecular weight with the conversion and a narrow molecular weight distribution (weight-average molecular weight/number-average molecular weight < 1.3). (c) 2006 Wiley Periodicals, Inc.