In this study, polypyrrole nanofiber (PPyNF)/NiO x composites were synthesized by a simple and fast microwave method. The samples were characterized using differential scanning calorimetry and thermal gravimetric analysis (DSC/TGA), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Furthermore, the synthesized PPyNF/NiO x nanocomposites were electrochemically characterized using galvanostatic charge-discharge, cyclic voltammetry and electrochemical impedance spectroscopy (EIS) techniques. They showed the highest specific capacitance of 657 F g -1 at 0.5 A g -1 , demonstrating their potential application in supercapacitors.