We report the electropolymerization of CuPtBr₆ film on the electrode substrate by cyclic scanning in 3×10⁻³ M CuCl₂+3×10⁻³ M K₂PtBr₆+1 M KCl in the potential range from +700 to −800 mV (versus the saturated calomel electrode (SCE)). Several surface analysis techniques were used to characterize the film on the electrode surface. A sharp and intense diffraction peak in the X-ray diffraction (XRD) pattern indicates that the film has a high preferential orientation. The electrochemical behavior of the modified electrode was studied in detail in electrolyte solutions containing various cations. On the basis of these studies, a mechanism of electropolymerization was proposed which suggests for the modifier film a one-dimensional, polymeric structure formed from a negatively charged platinum compound, stabilized by Cu²⁺ and Cu⁺ as the counter ions. The composition of the modified film is proposed to be [CuPtBr₆·CuPtBr₄]_n, and is denoted as CuPtBr₆/glassy carbon (GC) to highlight the starting components. H⁺/H, Fe³⁺/Fe²⁺ and Cr³⁺/Cr²⁺ display remarkably reversible redox behaviors at the CuPtBr₆/GC electrode. The modified electrode also displays good catalytic activity toward the oxidation of ascorbic acid, hydrogen peroxide, S₂O₃²⁻, and especially nitric oxide.