The removal of Rose Bengal dye (RB) from aqueous solution was tested by the adsorption process at initial dye concentration in the range of 3–50 ppm. For this purpose, a novel and sustainable Chitosan/Zirconium oxide nanocomposite (CS/ZrO2 NCs) was prepared by incorporating Zirconium oxide nanoparticles (ZrO2 NPs) into Chitosan nanoparticles (CS NPs). The prepared CS/ZrO2 NCs samples were characterized by many spectral techniques such as XRD, FTIR, SEM, EDX and TEM. The adsorption conditions such as dye concentration, contact time and CS/ZrO2 mass ratios were optimized. The experimental data shows that CS/ZrO2 containing 30% of ZrO2 NPs (CS/ZrO2 (30%)) has the highest adsorption capacity for eliminating RB dye among all the prepared samples. The maximum dye removal efficiency increased from 46% for Chitosan to 78% for the sample containing 30% of ZrO2 in CS/ZrO2 NCs. Isotherm models such as Langmuir and Freundlich were analysed. Kinetic studies indicated that Freundlich isotherm and pseudo-second order models are the best fitting for our experimental results.