In this study, the use of wheat bran as a possible adsorbent has been successfully demonstrated in the removal of Acid blue9 (AB9) from aqueous solution. The effect of different parameters such as temperature, adsorbent dose, contact time, adsorbent size and agitation speed were investigated. The optimum conditions obtained from response surface methodology are: temperature-38.1°C, adsorbent dose (3.1g/L), contact time (206 min), adsorbent size 0.1mm (150mesh), and agitation speed (222rpm). The effect of pH and initial substrate concentration were studied. The pseudo-first order and pseudo-second order kinetics were tested. The sorption equilibrium, expressed by the Langmuir and Freundlich equations, indicated that the process was in compliance with Freundlich isotherm.