We report an infant with a thoracic intradural extramedullary tumor to illustrate the presentation of an infantile spinal cord tumor and the difficulty in establishing a diagnosis. An infant presented with edema of the legs, motor loss in the lower extremities, and anuria at 3 months of age. Magnetic resonance imaging of the lumbar region did not reveal any abnormalities. At 1 year of age, the patient underwent surgery to correct urinary incontinence of unknown etiology. The patient developed gait disturbance and had abdominal pain at 17 months of age. Magnetic resonance imaging of the thoracic spine revealed an intradural extramedullary tumor at T2-T5. The spinal cord tumor was completely resected and pathologic findings indicated an endodermal cyst. All symptoms improved after the operation. Infants who present with weakness of the lower legs, urinary incontinence and unknown abdominal pain should be evaluated for a spinal cord tumor.