Ovarian-type surface epithelial neoplasms of the testis and paratestis are uncommon, and the mucinous subtype is particularly rare. These tumors represent a counterpart to ovarian cancer. Malignant tumors have the potential for metastatic spread and are often fatal. The case of a 59-year-old man with testicular mucinous adenocarcinoma is presented. Computed tomography indicated involvement of the paraaortic and pelvic lymph nodes, so chemotherapy was initiated. To the best of our knowledge, this is the second paper regarding responsiveness to chemotherapies used in ovarian cancer.