Electrochemically active ruthenium oxide (RuO_x⋅nH₂O), ruthenium oxide/hexachloroiridate (RuO_x⋅nH₂O/IrCl₆²⁻), and ruthenium oxide/hexachloroiridate/platinum (RuO_x⋅nH₂O/IrCl₆²⁻/Pt) hybrid films have been prepared from the mixture of Ru³⁺, IrCl₆²⁻, and PtCl₆²⁻ ions in an acidic aqueous solution. The repetitive cyclic voltammetry (CV) has been used for the film preparation process. The electrochemical properties and the growth mechanism of the above mentioned different kinds of hybrid films have been investigated using CV and electrochemical quartz crystal microbalance. The morphological and quantitative analyses have been carried out using scanning electron microscopy, atomic force microscopy and energy dispersive X-ray. Among these above mentioned films, RuO_x⋅nH₂O/IrCl₆²⁻/Pt hybrid film exhibits promising electrocatalytic activity towards the oxidation of arsenic oxide, methanol and reduction of oxygen. Further, detailed study of electrocatalysis using rotating ring disk electrodes and amperometric methods have been carried out for arsenic oxide oxidation and oxygen reduction reactions at the hybrid films. From the results, the sensitivity of RuO_x⋅nH₂O/IrCl₆²⁻/Pt hybrid film has been calculated for arsenic oxide as 0.7 mA mM⁻¹; and for oxygen as 1.8 mA mM⁻¹.