Nickel hydroxide nanosheets were synthesized by a simple microwave assisted heating method and investigated as electrochemical pseudo-capacitive materials for supercapacitors. The crystalline structure and morphology of the as-obtained Ni(OH)2 nanosheets were characterized by X-ray diffraction, nitrogen adsorption–desorption isotherms, field emission scanning electron microscopy and transmission electron microscopy. The electrochemical properties of the Ni(OH)2 nanosheets were evaluated by cyclic voltammetry and chronopotentiometry technology in 2 M KOH solution. The nickel hydroxide nanosheet electrode shows a maximum specific capacitance of 2570 F g−1 at a current density of 5 A g−1 and exhibits superior cycling stability. These results suggest its potential application as an electrode material for supercapacitors.