Manganese dioxide modified carbon powder was prepared via a wet impregnation method from the solution of permanganate salt. After heating at 120°C over night in air, the formation of manganese oxide was confirmed by cathodic stripping voltammetry. The synthesized material was used for fabrication of composite electrodes and their potential application in the field of electroanalysis investigated. The composite electrodes based on the manganese dioxide modified carbon powder proved to be useful as electrodes for detection of hydrogen peroxide, ascorbic acid and nitrite ions. © 2007 Wiley-VCH Verlag GmbH and Co. KGaA.