This is the first report about supercapacitive performance of hybrid film of manganese dioxide (MnO2) and polyaniline (PANI) in an organic electrolyte (1.0 M LiClO4 in acetonitrile). In this work, a high surface area and conductivity of active carbon (AC) electrode is used as a substrate for PANI/MnO2 film electrocodeposition. The redox properties of the coated PANI/MnO2 thin film exhibit ideal capacitive behaviour in 1 M LiClO4/AN. The specific capacitance (SC) of PANI/MnO2 hybrid film is as high as 1292 F g(-1) and maintains about 82% of the initial capacitance after 1500 cycles at a current density of 4.0 mA cm(-2), and the coulombic efficiency (eta) is higher than 95%. An asymmetric capacitor has been developed with the PANI/MnO2/AC positive and pure AC negative electrodes, which is able to deliver a specific energy as high as 61 Wh kg(-1) at a specific power of 172 W kg(-1) in the range of 0-2.0V. These results indicate that the organic electrolyte is a promising candidate for PANI/MnO2 material application in supercapacitors. (C) 2010 Elsevier B.V. All rights reserved.