The discharge of the first proton in the hydrogen evolution reaction on Ag(111) and Ag(110) has been investigated by potentiostatic pulses. For Ag(111), Tafel plots yield a straight line over the investigated range; however, the temperature dependence shows substantial deviations from the behavior predicted by the Butler-Volmer law. On Ag(110) the current density is substantially lower than on Ag(111), and the Tafel plots exhibit a change of slope.