Dawson-type 18-molybdodisulphate anion [S2Mo18O62](4-) has been immobilized within polypyrrole film by means of electrochemical polymerization. The polymer modified electrodes have been characterized with voltammetry and surface based techniques. The noticeable change in electrochemical properties of [S2Mo18O62](4-) has been observed with immobilization, which is favours its electrocatalytic performance. Hydrogen peroxide reduction in neutral pH as a standard system for electrocatalytic properties assessment has been studied on composite film-modified electrodes and showed the sensitivity of 127 mAM(-1) cm(-2). Developed system showed high stabilities towards redox switching and peroxide reduction. (C) 2018 Published by Elsevier Ltd.