Ornidazole is an antibacterial drug active compound. A glassy carbon electrode (GCE) was modified with an electropolymerized film of p-aminobenzene sulfonic acid (p-ABSA) in pH 7.0 phosphate buffer solution (PBS). The electrochemical properties of the polymer film were studied using cyclic voltammetry (CV) and different pulse voltammetry (DPV) techniques. The polymer film-modified electrode was used to electrochemically detect ornidazole. The polymer film showed excellent electrocatalytic activity for the reduction of ornidazole. The cathodic peak potential value of the ornidazole at the p-ABSA modified glasy carbon electrode was -513 mV obtained by DPV. A linear calibration curve for DPV analysis was constructed in the ornidazole concentration range 8x10(-7) -5x10(-5) M. Limit of detection (LOD) and limit of quantification (LOQ) were 1.00x10(-7) and 3.32x10(-7) M respectively. The DPV technique proposed was successfully applied to the detection of ornidazole in tablet dosage forms. Precision and accuracy of the developed technique were checked by recovery studies. The proposed method exhibits good recovery and reproducibility. The mechanisms of electropolymerization of p-ABSA and reduction of ornidazole at p-ABSA-modified GCE are also suggested.