A 26-year-old man was admitted to our hospital with a chief complaint of left cervical lymphadenopathy. He was diagnosed as having seminoma by needle biopsy. Computed tomography revealed an aorto-caval retroperitoneal tumor. Levels of lactic deydrogenase, human beta-chorionic gonadotropin, alpha-fetoprotein were not elevated. No abnormal findings were present on palpation and ultrasonography of the testes. The patient was diagnosed as having a retroperitoneal extragonadal germ cell tumor (EGCT). Three courses of chemotherapy (bleomycin, etoposide and cisplatin) and another course of chemotherapy (etoposide, ifosfamide and cisplatin) were performed. Complete remission was achieved. Seven years later, the patient noticed an enlargement of his right scrotal contents. Neither distant metastasis nor lymph node metastasis was detected by computed tomography. Right radical orchiectomy was performed and histology revealed seminoma with yolk sac tumor components. No recurrence has been seen after 10 months.