Diastematomyelia is an uncommon spinal dysraphism with midline dorsoventral clefting of the spinal cord. Formation of syrinx cavity within the hemicord, vertebral anomalies and lipomas is known to be associated with diastematomyelia. We present an unusual case of a 4-month-old girl, who presented with diastematomyelia and terminal myelocystocele, and dilatation of the terminal portion of the spinal canal with formation of a cystic structure. Findings were confirmed by subsequent surgery and histopathology. Ectopic right kidney, Chiari I malformation and changes of partial sacral agenesis were other findings noted in this case. No case report of formation of terminal myelocystocele arising from one hemicord was described in the literature we reviewed.