beta-Xylosidase recovery by reversed micelles using CTAB cationic surfactant was performed under different experimental conditions. A 2²-full orthogonal design with center points was employed to optimize the recovery of this enzyme and to evaluate the influence of the factors CTAB (A) and butanol concentration (B) on the enzyme extraction. A mathematical model to represent the enzyme recovery as a function of A and B was proposed. According to the model, the CTAB and butanol concentrations necessary to attain the maximum beta-xylosidase recovery (43%) were 0.26 M and 29.4%, respectively. The results showed that the recovery value predicted by the model was similar to that obtained experimentally (44.3%).