A striking development has been made in intracavitary and interstitial brachytherapy of head and neck tumors by the use of very active and very small ray emitters and, last but not least, by the step movement of the source developed 1974 in Essen and its computer optimization. The present study mentions 22 different sites of the head and neck area which have been treated by 31 different intracavitary or interstitial techniques, frequently under general anaesthesia. All application methods used here follow uniform rules for the dosage of the single application. Furthermore, generally accepted rules can be defined for the contra-indications of brachytherapy which, according to our experiences, should be strictly observed. The observance of these rules as well as the use of a radiobiological gap were among the reasons for the complete recovery of some cases of local recurrence which could be no longer treated by other methods.