The composite of polyaniline and reduced graphene oxide (PANI/RGO) was prepared through polymerization of aniline in the presence of graphene oxide, and further reduction by hydrate hydrazine. It was utilized as the effective adsorbent towards the adsorption of mercury(II) in aqueous solutions. As compared to PANI, the maximum adsorption capacity of PANI/RGO for Hg(II) was increased from 515.46 mg/g to 1000.00 mg/g and adsorption process was accelerated at pH 4.0. The superior adsorption was attributed to the presence of reduced graphene oxide which results 7 times enhancement in the specific surface area and the adsorption sites revealed by SEM, TEM and BET characterization. Co-adsorptive removal of dyes and Hg(II) can be realized using this adsorbent. (C) 2013 Elsevier B.V. All rights reserved.