Electrocatalytic activity versus oxygen evolution of perovskite-type cobalt oxide (La1-xCaxCoO3, with x = 0.0, 0.2, 0.4 and 0.6) was evaluated by potentiostatic polarization technique, as a function of the electrode chemical composition. Stability of the electrode material in alkaline medium under stressing galvanostatic conditions was investigated. Highly sensitive differential pulse adsorptive stripping voltammetry (DPAdSV) technique was successfully applied for determination of traces of dissolved cobalt in the electrolyte solution. The results point out the optimum electrode activity and stability of the x = 0.4 composition. (C) 2003 Elsevier B.V. All rights reserved.