A 77-year-old man visited our department with a painless mass in the left scrotum. He underwent left high orchiectomy with clinical diagnosis of testicular tumor. The tumor penetrated deeply into the internal inguinal ring. The tumor was resected as proximally as possible with positive surgical margin at the internal ring. Macroscopically, the left testis was intact in the resected specimen. Microscopic examination revealed that the tumor was consisted of myxoid stroma with spindle cells, and there was a large variation in histological findings. Immunohistchemical staining was positive with vimentin, and negative with alphaSMA, S-100, Myo D1, EMA, keratin, HMB45, and LCA. Accordingly, the tumor was diagnosed as myxofibrosarcoma, high-grade, of the spermatic cord. Postoperative CT scanning revealed multiple retroperitoneal lymph node metastases. He underwent radiation therapy, but soon developed lung metastases and pleural dissemination, and died 2 months after the operation. Myxofibrosarcoma, which had been called myxoid MFH is one of the most common soft tissue sarcomas. Myxofibrosarcoma or myxoid MFH of the spermatic cord is a rare disease. To our knowledge, only 7 cases have been reported in Japan to date.