The determination of the levofloxacin (LEV) antibiotic in biological samples (urine and Human serum) using cyclic voltammetry (CV) and square wave voltammetry (SWV) methods was investigated. A boron doped diamond (BDD) was used for the first time as a sensor in the above voltammetric methods. This electrode was used as anode whose electrochemical response showed three irreversible defined peaks. An oxidation mechanism of the molecule has been proposed, including a transfer of 2 electrons and 2 protons leading to LEV N-oxide. Under optimized conditions, CV is less sensitive than SWV method. The latter gave the lowest limit of detection and quantification. LOD and LOQ were found to be 2.88 and 9.60 mu mol L-1, respectively.