Gallium was electrodeposited from a synthetic Bayer solution comprising 4.5m NaOH/0.2m Na2CO3/0.3m NaCl/1.7m Al(OH)3. Hydrogen evolution occurred in parallel with gallium deposition, the latter process being in part controlled by mass transfer and in part by the electron transfer step. Combined coulometric and voltammetric measurements allowed estimation of a diffusion coefficient for Ga (III) of 3.6×10−6 cm2 sec−1 at 40° C. The coulombic efficiency for gallium deposition was a function of current density, deposition time, electrode rotation rate, temperature and gallium concentration. Values of up to 11% were obtained on a copper electrode from a solution containing 3.2×10−3m Ga (III). Heavy-metal impurities, such as iron and vanadium, usually found in these liquors, promote the hydrogen evolution reaction, completely inhibiting gallium production if present above certain critical concentrations.