Pharmaceuticals as an important group of contaminants of emerging concern (CECs) are unintentionally discharged into the aquatic environment due to lack of advanced treatment of classical wastewater treatment plants (WWTPs). Therefore, the detection and monitoring studies of pharmaceuticals and personal care products (PPCPs) in an aquatic environment are getting more important as well as the definition of their ecological risks to the aquatic ecosystem. To conduct these studies successfully, it is necessary to develop sensitive, robust, selective, and reliable methods to be able to analyze PPCPs. This study was carried out in the biological WWTP (BWWTP) of Erzurum City, Türkiye, to investigate the treatment efficiency of pharmaceuticals in the plant and to assess the ecological risks for the Karasu River where treated wastewater is discharged into it. For this purpose, a wide range of pharmaceutical classes in influent wastewater (IWW) and effluent wastewater samples taken from Erzurum BBWWTP, Türkiye was simultaneously identified and quantified with liquid chromatography coupled with tandem mass spectrometry following liquid phase extraction for sample preparation. A total of 55 active pharmaceutical groups in 25 general drug groups (29 subgroups) were detected, with the highest average ratios being 82.459%, 7.306%, 4.949%, and 2.145% for analgesic-anti-inflammatory, antiepileptic, diabetic, and antipyretic pharmaceuticals groups, respectively, in IWW. Although flurbiprofen from the analgesic-anti-inflammatory pharmaceuticals group was treated with the average efficiency of 66.13% during the 12-month treatment period, it had a high risk quotient due to the very high initial concentration in WWT in the range of 809.01-22,901.10 µg/L.