Study design: Cohort study. Objectives: The objectives of this study were examination, observation and surgical interventions of pediatric patients with diastematomyelia, a rare congenital deformity of the spinal cord. Setting: Spine surgery and neurosurgery clinic under ministry of health, the Russian Federation. Methods: Twenty children (1-18 years of age) with diastematomyelia participated in this study. Diagnosis was based on subjects' medical history, results of clinical examination, spine radiography in anteroposterior and lateral views, and neurophysiological examinations. Septum resection surgery was done in seventeen subjects. Results: All the subjects had skin manifestations along the midline of the back. Neurological symptoms were noted in 17 subjects: paraparesis in 11, urinary incontinence in 2, monoparesis in 4, and spasticity in 2 subjects. Three subjects did not show any neurological deficit. Orthopedic examination revealed spinal deformities of various degrees of severity. In 4 subjects, partial restorations of neurological functions were observed; and in 1 subject, bladder incontinence developed after the surgery. Conclusions: Patients who have limb length discrepancy, congenital scoliosis, skin manifestations should be examined for the presence of diastematomyelia. Patients having neither neurological deficit nor orthopedic deterioration should be monitored, and in case of deterioration, surgical treatment should be reserved. We advocate for performing resection of the septum in patients with diastematomyelia prior to surgical correction of scoliosis or orthopedic correction of lower limb deformities.