We report the direct homopolymerization and block copolymerization of 2-aminoethyl methacrylate (AEMA) via aqueous reversible addition-fragmentation chain transfer (RAFT) polymerization. The controlled "living" polymerization of AEMA was carried out directly in aqueous buffer using 4-cyanopentanoic acid dithiobenzoate (CTP) as the chain transfer agent (CTA), and 2,2'-azobis(2-imidazolinylpropane) dihydrochloride (VA-044) as the initiator at 50 degrees C. The controlled "living" character of the polymerization was verified with pseudo-first order kinetic plots, a linear increase of the molecular weight with conversion, and low polydispersities (PDIs) (<1.2). In addition, well-defined copolymers of poly(AEMA-b-HPMA) have been prepared through chain extension of poly(AEMA) macroCTA with N-(2-hydroxypropyl)methacrylamide (HPMA) in water. It is shown that the macroCTA can be extended in a controlled fashion resulting in near monodisperse block copolymers. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5405-5415, 2009