Various pharmaceuticals, active pharmaceutical ingredients and biologically active compounds are being found in the environment presenting serious treat for humans, animals and plants. Steroid estrogen 17 ß-estradiol is undesirable in the environment because of its influence on the hormonal and endocrine system of living beings. Therefore, the European Union, throughout its Directives addendums, listed E2 among the priority substances, actually E2 was placed at "watch" list of potentially harmful compounds which presence in the environment needs to be monitored. Currently available technologies for wastewater treatment can not effectively remove priority substances from water, thus development of new methods is highly demanded. Advanced oxidation processes provide an alternative or upgrade to the common conventional water treatment methods, therefore, this work was aimed at evaluation of applicability of UV-A/FeZSM5/H2O2 process for E2 degradation emphasizing the application of UV-A irradiation which exists in the global irradiation up to 5%. The experiments were directed to the investigation of the effects of selected process parameters; initial pH, the concentration of oxidant and the concentration of catalyst (iron-exchanged synthetic zeolite; FeZSM5) on the degradation of E2. In order to determine the optimal process parameters, Box-Behnken design of experiments with 3 process parameters on 3 levels was applied in combination with the response surface methodology (RSM). It was determined that all studied process parameters significantly influenced E2 degradation rate, but it should be pointed out that pH influence is the highest. The optimal conditions: pH 3, [H2O2] = 50 mM and [Fe] FeZSM5= 2.0 mM, yielded the maximum degradation rate of E2 of 8.31*10^-5 s^-1.