The cases of forty children who had incurred a spinal cord injury between birth and the age of eighteen years were reviewed at two to 26.8 years (mean, ten years) after injury. In all of the twenty-five patients who were injured prior to the adolescent growth spurt paralytic spinal deformity developed; in twenty-four (96 per cent) of them it was progressive. Scoliosis developed in twenty-three (92 per cent); kyphosis, in sixteen (64 per cent); and excessive lumbar lordosis, in five (20 per cent). Management of the spinal deformities by bracing was difficult, and seventeen patients (68 per cent) required spine fusion, usually to the sacrum. Complications were frequent. All of the fifteen patients who were injured after the onset of the adolescent growth spurt had sustained a spinal fracture or fracture-dislocation. Nine (60 per cent) had an acute angular thoracic or thoracolumbar fracture kyphosis and seven (47 per cent) had progressive fracture kyphosis. A history of a thoracic and thoracolumbar laminectomy always was associated with increased kyphosis progression. Six (40 per cent) of these patients required spinal stabilization, usually for unstable injuries and progressive post-laminectomy deformity. Progressive paralytic spinal deformity was uncommon in the postadolescent patient.