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.