Introduction & Objectives: Aniline is an organic compound widely used in various industries. The release of this compound has had various environmental impacts. Thus, the assessment of efficient and practical methods for the removal of aniline from wastewater of these industries is remarkable. Taguchi model is a model for the analysis of experiments, that predicts both the effects of each factors and the optimum level of them using a certain number of experiment. The purpose of this study was the optimization of aniline adsorption on the raw and modified BENTONITE with a cationic surfactant using Taguchi model.Materials & Methods: In this experimental study, the raw BENTONITE and modified BENTONITE was prepared in a few steps. Then, 4 main factors (i.e. pollutant concentration, contact time, pH, and adsorbent dosage) on 4 levels were selected by Matrix L16 trials and the experiments were conducted in this matrix. The factors were also ranked based on the R-value. Then, the data were analyzed with Minitab 17 software. Finally, the adsorption of aniline on raw and modified BENTONITE was determined in optimal conditions.Results: The optimization of adsorption process using Taguchi model showed that the factors of importance for optimizing respectively were: contact time of 360 minutes, pH =10 pH, aniline initial concentration of 300 mg/L and adsorbent dosages of 40 g/L. The maximum ad-sorption of aniline onto raw BENTONITE and modified BENTONITE with cationic surfactant in optimal conditions were determined 81.86 and 8.75, respectively. The results revealed that Freundlich isotherm and pseudo-second-order kinetic model provided a better to the ex-perimental data.Conclusion: The results showed that the BENTONITE modified with cationic surfactant is efficient in the removal of aniline. At the same time, since BENTONITE is cheap and easily accessible, it is considered a desirable adsorbant.