Different materials have been proposed as active electrode in electrochemical capacitors, including conducting polymers. Among them, several papers describe the use of polyaniline and its derivatives for such purpose. However, the use of poly(o-methoxyaniline), a polyaniline derivative, in ionic liquid electrolytes as pseudocapacitors has never been proposed in the literature. Therefore, the objective of this work is to investigate the electrochemical properties and stability of POMA casting film in ionic liquid electrolyte as electrode for supercapacitors. Cyclic voltammetry and galvanostatic charge/discharge experiments have been used to analyze the behavior of the films. The results show that POMA films have high specific capacitance and good electrochemical stability during 3000 cycles. Its initial value is 260 F g(-1) in a mixture of ionic liquid and polyethylene glycol (80:20 v/v). The specific energy shows 70% retention from the initial value after 3000 cycles. Furthermore, the specific power remains remarkably stable during 3000 cycles, as well as the coulombic efficiency, which is about 99%. For these reasons this work opens up the possibilities of using conducting polymers in ionic liquids and illustrates its good behavior and stability for supercapacitor application. (C) 2017 Elsevier Ltd. All rights reserved.