Degradation of ferrohexacyanide in aqueous solution by advanced oxidation processes was studied. Advanced oxidation processes included ozone and its combination with H2O2 and Ultraviolet radiation (UV). Results demonstrated that UV alone was not sufficient to degrade cyanide ion but an oxidant was required for complete degradation. Degradation of 100 mg/L cyanide in aqueous solution was pseudo-first order reaction at pH 11.0. Lower pH was avoided clue to formation of HCN gas but higher pH flavoured the degradation. A comparison of three systems i.e. O-3, O-3/H2O2 and UV/O-3/H2O2 showed that UV/O-3/H2O2 was the best system. The experimental results showed that the Optimum conditions for UV/O-3/H2O2 process for total cyanide degradation were obtained at lambda = 365 nm (400 W medium pleasure UV lamp), ozone concentration = 35 mg/L and H2O2 = 88.2 mM.