Poly(methyl methacrylate)s were successfully synthesized in a controlled fashion via reversible addition-fragmentation chain transfer polymerizations utilizing an automated synthesizer. Sixteen polymers were synthesized in a parallel way utilizing the Chemspeed Accelerator((TM)) SLT100 to investigate the reproducibility and the control over the polymerizations. The obtained polymers were characterized by gel permeation chromatography (GPC) and automated MALDI TOFMS measurements, thereby proving the reproducibility and controllability of the investigated automated setup. Furthermore, temperature optimization reactions were performed utilizing an individually heatable reactor block. Moreover, to demonstrate the presence of active polymer chains in the reaction mixture, chain extension polymerizations were performed on the automated synthesizer. The results obtained from these chain extension experiments demonstrate the possibility to design well-defined A-b-B block copolymers with different monomers as building units. (C) 2004 Wiley Periodicals, Inc.