Triblock copolymers were synthesized in aqueous dispersions in two polymerization steps using a low molar mass difunctional dithiocarbamate-based RAFT agent, and in merely one polymerization step using a macromolecular difunctional dithiocarbamate-based RAFT agent. Segmented block copolymers containing several alternating blocks of different polarities were synthesized in miniemulsion in merely two polymerization steps by applying multifunctional, dithiocarbamate-based RAFr agents. All polymerizations showed a linear increase of M-n with monomer conversion. Evidence that this novel synthetic concept resulted in the formation of (multi)block copolymers was obtained by combining normal gel permeation chromatography with gradient polymer elution chromatography. (c) 2005 Elsevier Ltd. All rights reserved.