Well-defined high molecular weight poly[2-(dimethylamino)ethyl methacrylates] [poly(DMAEMA)s] with molar masses up to similar to 1 x 10(6) g/mol were successfully synthesized via atom transfer radical polymerization (ATRP). This was achieved by using p-toluenesulfonyl chloride(p-TsCl)/CuCl/1.1.4. 7.10.10-hexamethyl-triethylenetetramine(HMTETA) initiator/catalyst complex in methanol/water mixture. Well-coutrolled/'living' behavior was demonstrated throughout the reaction, up to high monomer conversion. The PDI value remained low at 1.26 even for a polymer with very high molecular weight at 1.1 x 10(6) g/mol. We believe this is the first successful case where controlled ATRP produces a polymer with molar mass exceeding a million! (c) 2006 Elsevier Ltd. All rights reserved.