Over the last two decades the efficacy of many different accelerated fractionation schedules has been tested in a pilot and randomised clinical studies. Their results, especially on head and neck cancer, show that accelerated treatment has improved outcome, but in general an increased incidence and severity of acute mucosal reactions have occurred, and increasing rate of late morbidity has sometimes also observed. Furthermore, although the importance of time factor in radiotherapy of head and neck cancer is quite well documented, it is still difficult to separate the effect of treatment time from that of change in total dose, dose per fraction and/or interfraction intervals. This paper claims to arrange hitherto existing experiences of unconventional fractionation radiotherapy of head and neck cancer within the light of the own study designed in Gliwice, where overall treatment time is shortened by 2 weeks, giving one fraction per day, 7 days a week (CAIR).