A 37-year-old man was referred to our hospital with the chief complaint of infertility. Semen analysis at another clinic had demonstrated severe oligozoospermia and he had a history of bilateral orchiopexy for undescended testes. Scrotal ultrasonography revealed a hypoechoic heterogeneous mass (1.5 cm in diameter) within the left testis. With a provisional diagnosis of testicular tumor, left high orchiectomy was performed. Pathological examination of the tumor revealed seminoma. At 12 months after surgery, there has been no evidence of recurrence. Clinicians should be aware of the link between male infertility and testicular cancer, particularly following orchiopexy.