The adsorption ability of barley husk biomass for removing Cd (II) has been studied using cold vapour atomic absorption spectrometry. A dose of 3 g/L of dried biomass in a solution with an initial pH of 7, an initial Cd(II) concentration of 10 mg/L and a contact time of 90 min resulted in the maximum Cd(II) removal efficiency (95.9%). The effect of temperature on cadmium sorption on barley husk was thoroughly examined. Consistent with an exothermic reaction, an increase in the temperature resulted in decreasing Cd (II) adsorption rate. Thermodynamic parameters (i.e., change in the free energy (ΔGo), the enthalpy (ΔHo), and the entropy (ΔSo)) were also evaluated. The overall adsorption process was exothermic and spontaneous in nature. These results suggest that barley husk could be employed as an efficient adsorbent for the removal of cadmium from contaminated water sources.