In this study, environmental risks of selected pharmaceuticals were investigated to assess potential hazards. Ciprofloxacin, Clarithromycin, Cefuroxime axetil, antibiotics, Benzalkoniuman antiseptic, Paracetamol, an analgesic, and Naproxen, an anti-inflammatory, were selected due to their high rate of usage in Turkey. Ciprofloxacin was found to have the highest risk due to its high PEC/PNEC ratio (28.636). Benzalkonium, Paracetamol and Clarithromycin have a potential to cause environmental hazards. The biodegradation and biological concentration factors (BCF) of the drugs were also determined using EP.A/STWIN and EPA/BCFVVIN programs. The results illustrated that these pharmaceuticals are nonbiodegradable in wastewater treatment plants. The BCFs of Benzalkonium and Clarithromycin were found to be very high, 70.79011kg and 56.490 L/kg, respectively. It was suggested that alternative treatment methods other than biological ones should be investigated for these pharmaceuticals because of their low biodegradability. Also, unnecessary use of antibiotics is supposed to be discouraged to reduce environmental hazards. (C) 2014 Elsevier B.V. All rights reserved.