A series of Ni/reduced graphene oxide (Ni/RGO) composites were synthesized through a simple solvothermal method. Detailed characterizations of the composite using transmission electron microscopy and field emission scanning electron microscopy indicated that Ni particles were uniformly dispersed on the RGO surfaces. The electrochemical performances of Ni/RGO composites were much higher than their counterparts of Ni and RGO, because of the Ni particles being firmly decorated with the RGO nanosheets and the synergistic effect between both components. Among the prepared composites, Ni/RGO–2 exhibits the best electrochemical performance; namely, a high specific capacitance of 547.3 F g−1 is obtained in 2M KOH at 1 A g−1 and 81% of initial value is remained after a continuous cycling of 1000 times, which make it to be a promising electrode material for supercapacitors.