Extractive fermentation was employed for the production of phenylalanine using an agitated and aerated fermenter. Uncharged polystyrene beads ( Amberlite XAD-16) were packed in an external column and used to extract the phenylalanine in an intermittent fashion during the fermentation. Even though no cell separator was used and the fermentation broth was fed directly to the column, the overall system performed well without any clogging of the column. It was found that 43% of the phenylalanine could be extracted during the fermentation, and it was thus proved that extractive fermentation is an effective way to prevent the crystallization of phenylalanine. In addition, fermentation performance as also improved due to the relief of self-inhibition by phenylalanine. When 1.2 L of the beads was used and sufficient hydrophobic nutrients were present, the concentration and productivity increased 18% and 55% greater than in the control fermentation, respectively. These results show that extractive fermentation is a very attractive method to enhance production as well as to avoid crystallization. Numerical simulation modeling was also performed in this study for extractive fermentation. The results from the modeling corroborated the experimental data, thus confirming the reliability of the model.