In this study, starch-montmorillonite/polyaniline (St-MMT/PANI) nanocomposite was synthesized by chemical oxidative polymerization of aniline in the presence of St-MMT nanocomposite dispersion. The prepared ternary nanocomposite was characterized using FTIR, XRD, and SEM techniques. Adsorption properties of the nanocomposite were investigated for removal of reactive blue (RB 194) as a model reactive dye from aqueous solution. Response surface methodology was employed for the modeling of adsorption capacity of the nanocomposite. A second-order empirical relationship between adsorption capacity and independent variables (initial dye concentration, amount of the nanocomposite, and pH of the solution) was obtained. Pareto analysis for identification of the factors effect on the system revealed that initial dye concentration was the most effective parameter. The adsorption capacity value of reactive dye on St-MMT/PANI nanocomposite was 91.74 mg g(-1). Further investigations indicated that the adsorption experimental data were well fitted to the Langmuir isotherm and pseudo-second-order kinetic model. (C) 2013 Society of Plastics Engineers