Various aspects of technique in measurements of electrode kinetics under conditions where competing reactions due to the presence of trace impurities in the solution are important are examined.The kinetics of the hydrogen evolution reaction in acid and alkaline solutions on several transition metals has been examined with special reference to the low current density region. Inferences concerning the rate ‐determining step in the reactive are thus drawn. In general, there is a tendency for the metals examined in acid solution to have a rate‐controlling electrochemical desorption reaction and for those in alkaline solution to have a rate ‐determining discharge step.