We report a new effect in which hydrogen‐passivated acceptor impurities inp‐type GaAs are reactivated by low‐intensity, above band gap illumination. Low‐temperature photolumines cence was used to monitor the acceptor reactivation process. The light‐induced reactivation is persistent at cryogenic temperatures, but the material relaxes back to the hydrogen‐passivated state after annealing at moderate temperatures. Preliminary kinetic considerations, as well as the implications of this phenomenon on the fundamental and technological aspects of hydrogen passivation in semiconductors, are briefly discussed.