The tribological effects on hydrogen evolution in mild steel have been studied by the electrochemical extraction technique using a potentiostat as hydrogen detector. The amount of hydrogen evolved was measured from the evolution curve as a function of applied load, sliding time, and sliding velocity. The effect of dislocations due to the wear process on hydrogen trapping was also studied by using a gaseous permeation technique. Hydrogen evolution enhanced by the wear process was discussed in terms of the various factors causing hydrogen evolution using a simplified mathematical model. Thus, it is suggested that the tribologically driven hydrogen evolution in mild steel is mainly due to the removal of the highly segregated hydrogen layer and to the frictional heat in the initial stage of the wear process which then decreases to the steady state flux of hydrogen.