This study reports the synthesis, characterization, and application of chitosan coated zero valent iron nanoparticles (CTS-Fe-0) in the removal of Pb(II) from aqueous medium. This nano adsorbent showed a high adsorption capacity and efficient adsorption towards Pb(II) in aqueous medium. Adsorption of Pb(II) on CTS-Fe-0 obeyed pseudo-second order kinetics and was controlled by a film diffusion process. Among the various isotherm models the experimental data followed the Langmuir isotherm and the maximum adsorption capacity was found to be 666.6 mg/g at pH 5.0 and 318 K. The sorption mean free energy from D-R isotherm was found to be 72, 131, and 177 J/mol at 298, 308, and 318 K, respectively, indicating a physical sorption. The percentage of Pb(II) removal by CTS-Fe-0 particles is more than 90% at 318 K. The calculated thermodynamic parameters showed that the adsorption of Pb(II) is feasible, spontaneous, and endothermic in nature. Experimental results indicated that the CTS-Fe-0 appears to be a promising adsorbent for the removal of Pb(II) from aqueous media.