Reversible addition-fragmentation chain transfer (RAFT) polymerizations of styrene under microwave irradiation (MI), with or without azobisisobutyronitrile, were successfully carried out in bulk at 72 and 98 degrees C, respectively. The results showed that the polymerizations had living/controlled features, and there was a significant enhancement of the polymerization rates under MI in comparison with conventional heating (CH) under the same conditions. The polymer structures were characterized with H-1 and C-13 NMR. The results showed the same structure for both polymers obtained by MI and CH. Successful chain-extension experimentation further demonstrated the livingness of the RAFT polymerization carried out under MI. (c) 2006 Wiley Periodicals, Inc.