Composite electrodes for supercapacitors were prepared via electrochemical polymerization onto activated carbon. The capacitance properties were investigated using cyclic voltammetry (CV), AC impedance spectroscopy and charge–discharge tests. These electrodes show a specific capacitance of about 354Fg−1. This indicates that the in situ electro-polymerization of pyrrole onto carbon could improve the performance of carbon electrodes for use in supercapacitors.