The FeIII-TAML®/hydrogen peroxide system was first tested for decolorization of structurally different synthetic dyes. The kinetic of decolorization was greatly affected by pH. In alkaline medium the system is much faster, with more than 90% decolorization being attained within the first minutes. At pH 11, the treatment achieves over 98% degradation of the eight tested dyes within 15 min, and around 60% for another four dyes. Furthermore, when the performances of the oxidizing system were checked for decolorization of real textile wastewater, FeIII-TAML®/H2O2 showed promising results by a complete decolorization of the samples studied within 5 min at a temperature ranging between 25 to 40°C.