A new technique, which involves the continuous addition of a small amount of radical initiators, was developed with the assistance of computer simulation to increase the rate of nitroxide-mediated living free-radical polymerization. Using this method, the polymerization rate of styrene in the presence of 4-hydroxy-2,2,6,6-tetramethyl piperidinyl-1-oxy was increased more than 3-fold compared to that with one-batch addition of initiator, while the molecular weight and distribution remain the same, respectively, at higher monomer conversion. (C) 2000 Elsevier Science Ltd. All rights reserved.