Recently, researchers have shown an increased interest in removal of pharmaceutical residues by advanced oxidation methods because these residues reach up to drinking water supplies and adversely affect them. In this study, it was investigated to remove caffeine and paracetamol by UV and UV-H2O2 processes. The inlet and outlet concentrations for each residue were measured by LC-MS/MS instrument. UV and UV-H2O2 processes were carried out separately for each pharmaceutical residue. 45% and 100% treatment efficiency were achieved provided for caffeine and paracetamol respectively at the end of 30 minutes processing time in UV reactor alone. It was observed that UV reactor alone is not effective for the removal of caffeine. The UVH2O2 process was applied at different H2O2 concentrations. This application is aimed to determine the optimal H2O2 concentration for UV-H2O2 process. It was shown that the increase in concentration of H2O2 affects the removal positively for each pharmaceutical residue. In studies with UV-H2O2 process (5 mg/L H2O2) for caffeine and paracetamol; at the end of 15 minutes, 99% caffeine and at the end of 7,5 minutes 100% paracetamol removal were achieved. The results show that UV-H2O2 process provides more effective treatment for pharmaceutical residues than UV process alone. Higher removal efficiency needs longer reaction time in UV reactor and in this method wouldn’t be economical. Additionally, paracetamol could be removed in less time than caffeine in both processes.