This report describes a case of split cord malformation without a septum. A 2-year-old boy presented with a 3-month history of neurogenic bladder. MRI did not show any apparent abnormality around the conus medullaris. However, CT myelography clearly demonstrated the presence of a split filum terminale. The patient underwent laminectomy of L1-5 laminas and untethering of the split filum terminale. CT myelography was superior to MRI in diagnosing split cord malformation in this case. As MRI is currently regarded as the superior imaging modality, this reported case may have been missed because the pathology was not apparent on MRI.