Various thin films of Co-based alloys deposited by chemical and electrochemical methods have been tested as cathodes for hydrogen evolution reaction (HER) and anodes for oxygen evolution reaction (OER) in alkaline solutions. The results obtained with the SCP (Secondary Current Pulse) method, studying the electrochemical transients, are compared with amperostatic measurements. Surface coverage with the electrocatalytic films can be followed through SCP parameter values. A general frame is proposed for the interpretation of the electrokinetic behaviour on the base of the Normality-Inertia parameter. Co20Pt20 and Co20Pd80 electrodeposited thin films show interesting electrocatalytic properties towards H-2 and O-2 evolution, respectively.