Mucosal melanoma of the head and neck is a rare, poor prognosis tumour with a high tendency to recur locally and regionally after surgical resection. A number of centres have used radiotherapy to sterilize positive and close margins after non-radical surgery or to treat inoperable cases. The present article discusses the literature data to analyze the possible indications for radiotherapy in terms of patient selection and treatment strategy. In the majority of the available retrospective series, postoperative radiotherapy improves the local control of mucosal melanomas, but its effect on survival has not yet been sufficiently investigated. Radiobiological studies show a high heterogeneity in behaviour of irradiated melanoma cells and the clinical implications of this will be illustrated. In the future, a better understanding of the radiosensitivity of this rare tumour and the availability of new technical modalities might allow for a more profitable incorporation of radiotherapy into a multidisciplinary strategy.