Mesotheliomas are very aggressive tumours, almost exclusively caused by asbestos, which are very often occupational. Between 2014 and 2020, four out of five cases of testicular mesothelioma assessed at an institute were recognised as occupational diseases. The fifth case could not be classified due to lack of involvement of the affected person. However, all five cases were initially treated under a suspected diagnosis that was not related to mesothelioma of the testis. This shows the importance of histopathological examination of the surgically removed tissue.