Poly(N-2-aminoethylacrylamide) grafted magnetite nanoparticles were obtained via surface-initiated atom transfer radical polymerization of acrylamide on Fe3O4 nanoparticles and a subsequent transamidation with ethylenediamine. The final product was characterized by FT-IR analysis, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, wide angle X-ray diffraction, and vibrating sample magnetometry. As estimated by thermogravimetric analysis, the amount of grafted polymer on Fe3O4 and the grafting percentage were 75.0 mg/g and 9.61%, respectively. The efficiency of the synthesized nanoparticles was investigated against the removal of Cu(II) cations in optimum conditions by differential pulse voltammetry. The maximum adsorption capacity of the sorbent reached 30.34 mgig of Cu(II) at pH = 6.0. The adsorption kinetics followed the pseudo second order kinetic equation and the adsorption equilibrium data obeyed Freundlich isotherm model. The study of the re-usability of the prepared magnetic sorbent revealed that the sorbent could be re-used without a considerable decrease in the extraction efficiency and be recovered by 98.4% after seven cycles. These findings suggest that the prepared magnetic sorbent can be potentially applied to the effectual removal of Cu(II) cations from wastewater. (C) 2017 Elsevier B.V. All rights reserved.