The present work is concerned with the design and experimental testing of a fuzzy control algorithm for temperature control of a methyl methacrylate (NIMA) batch polymerization reactor. Ethyl acetate is used as solvent and benzoyl peroxide is the reaction initiator. The polymerization reaction is considered a challenge since it presents non-linear and transient behavior. The development of the fuzzy control and its comparison to a conventional PID (velocity form) controller is shown. In the design of PID-fuzzy control, the knowledge obtained from the process reaction curve procedure is employed to determine proper membership functions. Fine tuning is obtained altering the output scaling factor and cardinality. A digital filter was successfully used in order to overcome the oscillatory behavior of the temperature. According to experimental results, the PID-fuzzy was considered more suitable and reliable for this polymerization process control since it outperformed PID velocity form algorithm. (c) 2005 Elsevier Ltd. All rights reserved.302268276