In this article we presented a case of 56-year-old gentleman who developed massive scrotal swelling secondary to malign mesothelioma of the tunica vaginalis testis. Transscrotal ultrasonography revealed a cystic mass attacted to the tunica vaginalis on the inferior surface of the left testis. Testicular tumor markers were normal. Metastatic workup, including abdominal and chest computerized tomography scan were also normal.