A comprehensive experimental investigation of nitroxide-mediated radical polymerization (NMRP) of styrene using 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) as controller is presented. Polymerizations with a bimolecular initiator (benzoyl peroxide; BPO) were carried out at 120 and 130 degrees C, with TEMPO/BPO molar ratios ranging from 0.9 to 1.5. Results indicate that increasing temperature increases the rate of polymerization while the decrease in molecular weights is only slight. It was also observed that increasing the ratio of TEMPO/BPO decreased both the rate of polymerization and molecular weights. Probably for the first time in the history of such investigations, the paper contains a comprehensive database, appropriate for parameter estimation in aid of future modelling studies, since it comes from a systematic data collection containing independent replication.