We have measured the photoluminescence properties of laser‐annealed single‐crystal GaAs. The quantum efficiency of the band‐edge emission at liquid helium temperatures was increased by 3 orders of magnitude after a single 10−3‐s pulse of ruby laser light. This increase in radiative efficiency is thought to be due to dissociation of Si‐donor‐Ga‐vacancy complexes, which is expected to decrease nonradiative processes and possibly increase radiative centers. A theoretical prediction of the temperature distribution at the end of the laser pulse was performed.