In this study, Cd(II)) ions imprinted poly(hydroxyethyl methacrylate-N-methacryloyl-(L)-cysteine methylester) pHEMAC nanoparticles was prepared for the oral treatment of heavy metal poisoning. Cd(II) ions imprinted pHEMAC nanoparticles were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), zetasizer, and surface area calculations. The efficiency and selectivity of these Cd(II) ions imprinted pHEMAC nanoparticles were investigated both in deionized water and simulated gastrointestinal fluids. Adsorption studies were performed at different pH, temperature and initial concentrations of Cd(II) ions to determine optimum conditions. The selectivity studies were accomplished with Cd(II) ions imprinted and non-imprinted pHEMAC nanoparticles by using different metal ion solutions (i.e., copper, zinc, nickel, and lead ions). Langmuir and Freundlich isotherms were applied for these adsorption studies.