Pharmaceuticals as chemical compounds used for treatment, have undoubtedly a positive effect on human health and life in general. However, due to the increasing need for use, they are discharged into the environment in various ways and they are called new pollutants. One of the most commonly detected pharmaceuticals in the aquatic environment is diclofenac (DCF). In water has been found pharmaceuticals and other micro-pollutants even after procceses which are part of conventional treatment systems. Therefore, it is important to research water treatment methods that can eliminate them in an efficient, environmentally and economically acceptable manner. Advanced oxidation processes, especially photocatalysis, are highlighted. The aim of this work was to investigate the potential of photocatalytic advanced oxidation processes with simulated solar radiation to remove DCF from water. The TiO2 – Fe2O3 composite was prepared by hydrothermal synthesis. The adsorption affinity of the composite according to DCF was investigated and the composite was prepared by sol-gel method immobilized on glass tiles. The efficiency of DCF removal by the solar / TiO2 – Fe2O3 process was also investigated. It was found that the best adsorption properties showed a composite with a content of 3% Fe2O3, it was showing a higher adsorption potential than composites with increasing Fe2O3 content (9% and 15%). Also, by the photocatalytic process, decomposition was achieved. 44.5% DCF removal was achieved at pH 4 using TiO2 – Fe2O3 photocatalysts (15%), whereas the conversion in this case was 1.1%. On the other hand, in the system with TiO2 – Fe2O3 (3%), a removal of 37.9% was achieved, while the conversion was 16.8%.