A treatability study of pharmaceutical wastewater from El-Nasr Pharmaceutical and Chemical Company, South-East of Cairo, was carried out. The company discharges both industrial (6000 m(3)/d) and municipal wastewater (128 m(3)/d) into a nearby evaporation pond without any treatment. The generated raw wastewater is characterized by high values of COD (4100-13,023), TSS (20-330 mg/L), and oil grease (17.4-600 mg/L). In addition, the presence of refractory compounds decreases BOD/COD ratio (0.25-0.30). Analysis of raw wastewater confirmed that pre-treatment is required prior to discharge into public sewers to comply with the Egyptian Environmental laws and regulations. The obtained results indicated that the refractory compounds and their by-products cannot be readily removed by biological treatment and always remain in the treated effluent or adsorbed on the sludge flocs. The application of Fenton oxidation process as a pre-treatment improved the removal of pharmaceuticals from wastewater and appears to be an affective solution to achieve compliance with the law legislation with respect to discharge in a determined receptor medium. (C) 2009 Elsevier B.V. All rights reserved.