The temperature control strategy of a fed-batch reactor has been presented. The fed-batch operation is very useful to increase the productivity in some type of batch reactors but may incur in reactant overdose, which in case of exothermic reaction would result in possible runaway condition. The main problem is to get the best feeding profile (temporal trajectory) to minimize the reaction time with a temperature constraint. The genetic algorithm (GA) has been used for this task and the profile obtained has been used to drive a pilot scale experimental reactor. This work also demonstrates the usefulness of the GA in parameter estimation of first principle models.