The NiMoO4 catalyst has been obtained by a precipitation method under a controlled pH condition and characterized ex situ by infrared, X-ray diffraction, Brunauer–Emmett–Teller (BET), and particle size, and in situ by cyclic voltammetry, impedance and steady-state anodic Tafel polarization techniques. Results show that NiMoO4 has pure crystalline monoclinic phase with the crystallite size ~50 nm and the lattice constants, a = 9.597 Å, b = 8.765 Å, c = 7.667 Å, and β = 114.22°. Values of the average particle size and BET surface area of the oxide powders are found to be 730 nm and 11.75 m2/g, respectively. The oxygen evolution reaction follows the first-order kinetics with respect to OH− concentration, the Tafel slope being ~70 mV.