Previous modeling techniques of P–N junctions have been applied for studying the annealing of Gamma-ray damage in power MOSFETs. The degradation of the physical parameters of the body-drain junction for a dose rate of 103.8 rad/min is presented. Large decrease of the reverse recombination current, of the series resistance and of the ideality factor are shown to be related to the thermal anneal. These effects are discussed and explained by the evolution of the radiation-induced defects.