Data obtained in our experiments indicate that the microwave sterilization system utilized may be considered as a practical and rapid method for decontaminating steel surgical instruments. For the tested organisms (7 Gram- and 2 Gram+ genera) a 3' exposure time to microwaves provides successful sterilization. Microwave irradiation also had a killing action against Bacillus subtilis spores. A study by SEM of microwave treated spores shows typical morphological alterations of spore surfaces.