Malignant mesothelioma (malignant adenomatoid tumour) of the tunica vaginalis testis is a very rare neoplasm with highly aggressive biological behaviour. Treatment is difficult, and widespread local invasion and/or metastatic disease at presentation are associated with a poor prognosis. In this case report we describe for the first time a patient who, despite presenting with locally advanced disease, remains well 10 years after diagnosis and treatment with radical orchidectomy and high dose radiotherapy.