We introduce a facile method for the construction of graphene oxide/polypyrrole (GO/PPy) nanocomposites via one–step coelectrodeposition. In this process, the relatively large anionic GO serves as a weak electrolyte and is entrapped in the PPy nanocomposites during the electropolymerization of pyrrole, and also acts as an effective charge-balancing dopant within the PPy film. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) results demonstrate that the GO/PPy nanocomposites are successfully synthesized. The obtained GO/PPy nanocomposites exhibit good electrochemical properties and cycling performance, indicating a synergistic effect of PPy and GO. Taking its higher capacitance, lower cost and shorter processing time into consideration, GO may be a good choice for the fabrication of electrochemical supercapacitors based on conducting polymer nanocomposites. It should be noted that this coelectrodeposition is also applicable for the graphene oxide/poly[3,4-ethylenedioxythiophene] (GO/PEDOT) nanocomposites. Moreover, this facile and effective approach for the synthesis of GO/conducting polymer nanocomposites further extends the application of GO and should be very promising for the fabrication of inexpensive, high-performance electrochemical supercapacitors.