Most patients presenting with malignant mesothelioma of the pleura (MMP) are only suitable for palliative treatment. Radiotherapy has not been shown to improve survival in patients with this disease, but is of use in the palliation of symptoms. In this retrospective review of 111 patients with MMP referred to the Peter MacCallum Cancer Institute, the palliative effect of radiotherapy was analysed. More than half of the patients whose response could be assessed had some symptomatic relief from the radiotherapy treatment. No dose-response relationship could be found.