In this work, the starch extracted from potato peels was modified with acrylic acid. Nanoparticles composed of modified starch polymer and Fe3O4 (modified potato starch-magnetic nanoparticles, MPS-MNPs) were synthesized. The prepared nanoadsorbents were used for selective exclusion of Pb 2+ , Cu 2+ , and Ni 2+ ions from water. They were characterized by different analytical instruments such as FTIR, TEM and XRD. Adsorption of all captured metal ions onto MPS-MNPs was observed to be reliant on temperature, pH and contact time. Clump adsorption balance was come to in 60 min and most extreme uptakes for Cu 2+ , Pb 2+ and Ni 2+ in non-aggressive adsorption mode were 100, 70 and 100 mgg −1 , respectively at 35 â—¦C. In focused adsorption tests, PS-MNPs specially adsorbed Ni 2+ ions with an affinity order of Ni 2+ >Cu 2+ >Pb 2+ . The effect of monomer and initiator concentrations on grafting process was studied. Furthermore, the recyclability of PS-MNPs was investigated.