This work aimed to study the biosorption of metal ions by chitosan beads, conducted at room temperature by adding chitosan beads into a conical flask containing different initial pH. The flask was agitated, and the concentrations of metal ions were determined using inductively coupled plasma-optical emission spectrometry (ICP-OES). It was found that the sorption percentage and capacity on the effect of pH for metal ions increased with pH and hit a plateau at pH 3 for single-metal solutions, while binary-metal solutions hit a plateau at pH 2. A consideration separation of Au(III) from Cu(II) could also be achieved at pH 3-5. Keywords: biosorption; chitosan beads; Au(III); Cu(II) eISSN: 2398-4287 © 2022. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BYNC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians/Africans/Arabians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. DOI: https://doi.org/10.21834/ebpj.v7i21.3667