In this study, magnetic Fe@MgO nanocomposites were synthesized by a facile precipitation-calcination method, and used for heavy metal ion and dye removal from water. The as-synthesized Fe@MgO core-shell nanocomposites exhibited large surface area with mesoporous structure and high magnetic saturation value facilitating magnetic separation. Fe@MgO nanocomposites showed excellent adsorption properties, with maximum adsorption capacities of 1476.4 mg.g(-1) for Pb(II) and 6947.9 mg.g(-1) for methyl orange (MO), respectively. The adsorption processes of Pb(II) and MO onto Fe@MgO were found to well follow the pseudo-second-order kinetic model and Langmuir isotherm model, indicating monolayer chemisorption behaviors. Mechanisms of Pb(II) and MO adsorption onto Fe@MgO were investigated by analyzing the adsorbed products. It was found that a little of MO might be mineralized by Fe@MgO. Additionally, Fe@MgO nanocomposites could simultaneously remove Pb(II) and MO from water, and Pb(II) could promote the MO adsorption onto Fe@MgO. Therefore, Fe@MgO nanocomposites are believed to have high potential in environmental remediation for heavy metal ion and dye removal. (C) 2017 Elsevier B.V. All rights reserved.