The paper considers the impact of a powerful short-term microwave radiation (f= 2.45 GHz) on defect states of CdS monocrystals with the aid of investigation of the luminescence spectra in a domain of 0.6–2.5 μm at 77 K. It has been found experimentally that the microwave processing affects the luminescence characteristics of the crystals because of a change in concentration of cation vacancies (centers of photosensitivity) and in concentration of centers of fast (nonradiative) recombination. The results of the investigations point to the prospects in applying the microwave radiation in technological processes for the control of photosensitivity and of the luminescence spectra of cadmium chalcogenide