© 2020 Elsevier B.V.The electrochemical oxidation of an oxazolidinone class of antibiotic, Linezolid (LNZ) was studied in aqueous as well as aqueous/surfactant media on a commercially available boron-doped diamond (BDD) electrode pretreated cathodically. By using cyclic voltammetry, LNZ showed two couples of oxidation/reduction peak in aqueous solutions. The electrode process is pH-dependent and controlled by diffusion. The compound yielded two well-separated oxidation steps in acidic, neutral and alkaline media by employing square-wave voltammetry. The sensitivity of the voltammetric measurements was improved when the cationic surfactant, cetyltrimethylammonium bromide (CTAB) was present in the electrolyte solution at pH 4.0. In Britton-Robinson buffer containing 0.9 mM CTAB, the calibration curves were linear for both oxidation peaks (Ia and IIa) over concentration ranges of 0.25–6.41 μg mL−1 (0.74–19.27 μM), with detection limits of 0.05 μg mL−1 (0.15 μM) for Ia, and 0.12 μg mL−1 (0.34 μM) for IIa. The practical applicability of developed methodology was tested in pharmaceutical formulations.