The good response of inflammatory diseases to a low dose radiotherapy is well known. Mainly, this fact is based on experiences made in the time before antibacterial chemotherapy area. In this study our results are presented which were obtained by treating 90 patients with radiotherapy in the last years, exlusively. With respect to the end of the treatment a success rate of more than 90% was achieved. This result was compared with literature and with own findings from radiotherapy of patients with degenerative joint diseases. From the viewpoint of radio-protection the radiotherapy should be initiated as early as possible because in these cases better results could be attained at low doses. Especially, the radiotherapy of the following diseases seems to be favourable: parotitis, mastitis, abscess, furuncle, paronychia and panaritium. Besides the complications and risks of the chemotherapy the somatic and genetic radiation injuries are discussed. When radiation therapy is applied skilfully the side effects of a locally and regionally limited therapy may be neglected. It is recommended to extend the indication for radiotherapy of inflammatory diseases.