Heavy metal pollution is a serious environmental problem that can be remediated by various adsorbents. So, a new hydroxyapatite / graphene oxide nanocomposite (HAp/GO) material was synthesized from waste eggshell as a green and eco-friendly adsorbent for the effective removal of heavy metals (e.g., Cd, Pb, Cr, Ni, Co) from wastewaters. Nano-structured HAp was synthesized by calcination of the waste eggshell followed by hydrothermal treatment in the presence of phosphate solution. However, GO was synthesized using the Hummar's method (Guerrero-Contreras and Caballero-Briones, 2015). The HAp/GO nanocomposite was synthesized from the HAp and GO precursors by ultrasonic treatment. The morphology, composition, crystal structure, functionality and stability of the synthesized sorbent were evaluated using Fourier transform infrared spectrophotometry (FTIR), high-resolution transmission electron microscopy (HR-TEM), scanning electron microscope (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), Raman spectrometry and N₂-BET (Barrett–Emmett–Teller) surface area measurement techniques. The equilibrium concentrations of heavy metals were measured using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The effect of the initial concentration of heavy metals, the dosage of HAp/GO, temperature effect and the solution pH on the adsorption capacity was investigated. The synthesized HAp/GO was adopted to achieve superior simultaneous removal efficiencies (≥ 90 %) for (Cd, Pb, Cr, Ni, Co) metal ions. .