Recurrence of a head and neck tumour in a previously irradiated area presents a challenging problem. The preferred therapy for patients with such a recurrence is still surgery, but only a minority of patients with limited-volume disease are eligible for resection with a curative intent. Side effects, functional and cosmetic, can also be severe from surgery. Systemic therapy is most often offered to patients with unresectable disease but is palliative with little chance of a cure. Reirradiation can be given with or without pharmacotherapy and long-term survival has been reported in several institutional and cooperative studies. Therefore, reirradiation has emerged as the only treatment with a potential for cure except for surgery. However, most reports also describe that reirradiation can be dramatically toxic, including treatment related deaths. The selection of patients for this kind of treatment seems to be crucial, but only few data exist in the literature to serve as guidelines and aid in this selection process. Predictors of successful treatment outcome seem to be a reirradiation dose above 60 Gy (2 Gy/fraction, delivered daily, 5 times a week or with schedules with equivalent BED), a long interval between radiotherapy for the primary tumour and reirradiation, and if the new tumour is a second primary and not a true recurrence. Intensity modulated radiotherapy (IMRT) is a technique that is increasingly used and may reduce toxicity and probably improve disease control. Novel systemic therapies and radiotherapy techniques, stereotactic body radiotherapy, and protons are under active study.