Background: The use of antibiotics and other pharmaceuticals and therefore their input into sewer system, sewage treatment plants and in the aquatic environment is of increasing concern. Clinical and urban waste water as sources of high amounts of pharmaceuticals play an important role in the assessment of environmental exposure and risk. The subjects of this study are options and limits of the monitoring of antibiotics in diverse waste water. Material and Methods: Samples of mixed wastewater of the influent and the final effluent of the sewage treatment plants and hospital waste water were measured. Sewage samples were prepared with solid phase extraction, separated with HPLC and detected with tandem mass spectrometry. Results: The most prescribed antibiotics amoxicillin, azithromycin, cefuroxime, ciprofloxacin, clarithromycin, clindamycin and its metabolite clindamycin sulfoxide, doxycycline, levofloxacin, penicillin V, roxithromycin, sulfamethoxazole, and trimethoprim and the often in hospitals used antibiotics cefotaxime and piperacillin were continuously detected. This mean the analytical method is suitable for antibiotic monitoring. The simultaneous measurement of the influent and the final effluent showed the elimination efficiency of the sewage treatment plant. Amoxicillin, cefotaxime and penicillin V were not found in the effluent and a significant decreasing concentration of cefuroxime, ciprofloxacin, and levofloxacin was observed. The variability of the composite of hospital waste water is very high and a monitoring with short time segments is necessary to determine the deviation. Conclusions: The developed monitoring of antibiotics is suited for characterization of diverse waste water of sewage treatment plants with a justifiable operating expense. The measurement of hospital waste water and samples of the sewage network are possible.