This work is dedicated to the removal of free cyanide from aqueous solution through oxidation with hydrogen peroxide H2O2 catalyzed by copper-oxide nanoparticles. Effects of initial molar ratio [H2O2]0/[CN−]0, catalyst dose, temperature, pH and the catalyst stability on cyanide removal have been investigated. The use of copper-oxide has improved the reaction rate showing catalytic activity. The cyanide removal efficiency was increased from 60% to 94% by increasing in the dose of catalyst from 0.5 g/L to 5.0 g/L. Increasing the temperature from 20 °C to 35 °C promotes cyanide removal and the four successive times re-use of catalyst shows good stability. Kinetics of cyanide removal was found to be of pseudo-first-order with respect to cyanide. The rate constants have been determined.