In this paper, calcite with cotton morphology was prepared by co-precipitation method using cotton as templates. The effect of contact time, initial concentration, and solution temperature on calcite adsorption of lead ions was studied using a batch technique. The maximal adsorption capacity of calcite for Pb2+ was 3347.02 mg/g with a minimum contact time of 60 min. The pseudo-second-order kinetic model and Langmuir/Freundlich isotherms were proposed for modeling kinetic and equilibrium data, respectively. Thermodynamic parameters such as a dagger G (0), a dagger H (0), and a dagger S (0) were calculated to reveal the nature of sorption. Original calcite and the products of adsorption were characterized using SEM, TEM/EDAX, SAED, XRD, and BET. Dissolution of calcite followed by precipitation of lead carbonate was found to be the main operating mechanism for Pb2+ adsorption by calcite.