Cadmium oxide (CdO) nanoparticles were prepared using cetyl trimethyl ammonium bromide (CTAB) as surfactant by the co-precipitation method. Cadmium oxide nanoparticles have many advantages, such as remarkable catalytic activity, a simple preparation procedure, and long-term stability of signal response during of Zolmitriptan (ZLM) oxidation in phosphate buffer solution at pH 3.02. The synthesized CdO, TiO2 and morphology of the composite surface was examined by scanning electron microscopy. The electrochemical behavior of ZLM at the composite sensor was investigated and the results indicate that the electrode reaction is controlled by the diffusion process. The established sensor exhibited fast response, excellent electrocatalytic response high sensitivity, good reproducibility, and stability. (C) 2013 The Electrochemical Society. All rights reserved.