A 13-year-old boy presented with a large painless scrotal mass and underwent radical orchiectomy with the presumptive diagnosis of testicular tumor. The diagnosis was epididymal leiomyoma (EL). The treatment of paratesticular tumors is excision of the tumor without orchiectomy whenever possible. Even when the epididymal origin of the tumor is detected during operation, it may be impossible to spare the testis because of the tumor's large size or incorporation of the testis into the tumor mass. This case is presented because of the extremely rare incidence of epididymal tumors and of EL and to emphasize the diagnosis and treatment of epididymal tumors.