Pharmaceuticals compounds are widely used to maintain human and animal health worldwide. After human consumption pharmaceutical compounds in the urban aquatic environment reach to the wastewater facilities and eventually find their way to the surface waters. Aim of this study was to determine the effects of various sludge retention times (SRT) and hydraulic retention times (HRT) using lab-scale continuous stirred tank reactor (CSTR) for the removal of diclofenac and paracetamol in activated sludge. In order to find out removal rates of these pharmaceutical compounds, activated sludge reactor were operated at different sludge retention times (SRT: 10, 20, 30 days) and different hydraulic retention times (HRT: 12 and 24 hours). The highest removal rates were obtained under 30 days of SRT and 24 hours of HRT operating conditions. Maximum removal of 95% was observed for paracetamol and 44% for diclofenac. The operational implementation of SRT and HRT has been shown to increase the removal efficiency of pharmaceutical compounds.