Radiotherapy is an important treatment modality for head and neck cancers, both as definitive treatment and as adjunct treatment after surgery. Complications are common after radiotherapy for head and neck cancer owing to irradiation of many normal tissues and structures with important functions related to daily activities. Of these, late oral complications are of particular concern because of their effect on many basic functions, such as speech and swallowing. Although late complications following radiotherapy have been recognized for many years, recent developments in the treatment of head and neck cancers may have a significant impact on the incidence and severity of late complications. This article examines the current issue of late oral complications after radiotherapy, with an emphasis on the impact of recent advances in cancer treatment.