Primary germ cell tumors may spread to the lung, liver, brain, and bone hematogenously. However, spinal metastasis is extremely rare. A case with yolk sac tumor (YST) and cauda equina metastasis was presented in a 2-year-old boy. Two months prior to admisssion, he underwent left radical orchiectomy for testicular YST. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed spinal and cauda equina involvement. This is the first report of metastasis of testicular YST to cauda equina in a child.