Electroless cobalt on the surface of spherical nickel hydroxide has been used as a surface modifying method of active material for positive electrodes of rechargeable alkaline batteries. Cyclic voltammetric studies show that the electrodes exhibit higher oxygen overpotential and much more reversibility than ones of pure nickel hydroxide or nickel hydroxide with 5 wt.% cobalt added as a conductor. The discharge behaviour of the electrodes is also similar.