The aims of this work are to evaluate the presence of antibiotics in surface waters in a French water basin, where the presence of livestock is relatively important, and to understand the behaviour of antibiotics in drinking water treatment plants (DWTPs). Two sampling sites were chosen because of their livestock density and the presence of DWTPs in areas where urban activities are different. A large range of veterinary and human antibiotics were analysed in raw and treated water from the French Seine-Normandy Basin, based on the development of two analytical methodologies using solid-phase extraction and high-performance liquid chromatography-mass spectrometry. Clorsulon (an anthelmintic), fluoroquinolones, macrolides, sulfonamides (such as sulfamethoxazole, sulfadiazine), tetracyclines and trimethoprim were detected in raw surface water. Regarding the efficiency of drinking water treatment, an ozone/granular activated carbon combination proved to be effective in removing most antibiotics except danofloxacin and enrofloxacin which have an ionisable character and insufficient ozonation kinetic constant. Chlorination proved to be ineffective in removing antibiotics passing through the previous stages.