Radiotherapy plays an important role in the treatment of head and neck cancer. It represents the main curative option in advanced tumors. Due to technical progress of treatment appliances, the translation of radiobiological research into clinical praxis (altered fractionation), and the concurrent application of chemotherapy (radiochemotherapy), the efficacy of radiotherapy has markedly improved. Current developments focus on the integration of functional imaging into the treatment planning process to allow individualized dose prescription. Different systemic agents have shown to improve prognosis when applied concurrently with radiotherapy, whereas induction chemotherapy has not proven to be of further benefit. Treatment of human papillomavirus-related oropharyngeal carcinomas is challenging. Reduced treatment intensity for this entity is being investigated but cannot be recommended for clinical routine at this point. Adjuvant radiotherapy and radiochemotherapy improve the prognosis in high-risk head and neck cancer after surgical treatment. Further reductions in the treated neck volume in adjuvant radiotherapy need clinical investigation.