Considerable interest has been shown in recent years about hyperfractionated and accelerated radiation therapy for head and neck squamous cell carcinomas. The first randomized trial showing an advantage for hyperfractionation in terms of tumor control was the European Organization for Research and Treatment of Cancer 22791 trial. More recently, accelerated radiotherapy has been tested in many studies showing that high total doses of radiation could be delivered in overall treatment time shorter than conventional radiation therapy. The benefit of accelerated radiation therapy has been reported in some recently completed randomized trials, which suggests that rapid repopulation of surviving tumor cells during radiation therapy is a major determinant to obtain cure in this type of cancer.