This study describes an effective method developed for the removal of hexavalent chromium, Cr(VI), from anaqueous environment. In this study, the Ni–SiO$_2$ nanomaterial was synthesized by the sol–gelmethod and then characterizedby field emission scanning electron microscopy, X-ray diffraction and energy dispersive X-ray spectroscopy. The preparednanomaterial was then employed as an adsorbent with significant properties of high surface area and uptake capacity.Adsorption conditions of Cr(VI) onto the Ni–SiO$_2$ nanomaterial were optimized by altering different parameters (pH, initial Cr(VI) concentration and different periods of time). An amount of 100.75 mg g$^{−1}$ was estimated as the maximum uptakecapacity of the Ni–SiO$_2$ nanomaterial at pH 4.0. The experimental data of Cr(VI) adsorption onto the Ni–SiO2 nanomaterialwere fitted well to the Langmuir isotherm and pseudo second-order kinetic models.Moreover, the adsorption of Cr(VI) ontothe Ni–SiO$_2$ nanomaterial was not influenced even in the presence of different coexisting ions. Finally, the recommendedmethodology was applied on several environmental water samples.