A maghemite nanoparticles modified with homopolymers of a new mercaptoethylamino monomer (MAMNPs) have been prepared. The MAMNPs nanoparticles were fully characterized by FT-IR, XRD, BET and TEM measurements. The influences of parameters including pH, dosage of adsorbent and contact time have been investigated in order to find the optimum adsorption conditions. Metal ions adsorption process was thoroughly studied from both kinetic and equilibrium points of view. MAMNPs showed high tendency to investigated metal ions, in this order: Ag(I) > Hg(II) > Pb(II) > Cd(II), owing to the strong contribution of surface loaded polymer.