Late relapses are exceedingly uncommon in patients with pathologic stage (PS) I non-seminomatous germ cell tumors (NSGCT) of the testis treated with inguinal orchiectomy and retroperitoneal lymph node dissection (RPLND). We describe an unusual patient with PSI NSGCT who relapsed 40 months after surgery. The only evidence of recurrent disease was an elevated serum α-fetoprotein level, and complete remission was achieved following the prompt institution of combination chemotherapy. To our knowledge, this is the first report of a late relapse in PSI NSGCT of the testis manifested only as an elevated tumor marker.