Study Design. A retrospective analysis of patients that underwent perioperative halo-gravity traction as an adjunct to modern instrumentation methods in the treatment of severe scoliosis and kyphosis. Objective. To review the clinical and radiographic results of perioperative halo-gravity traction in several time periods. Summary of Background Data. Few reports to our knowledge review the use of perioperative and intraoperative halo-gravity traction in this patient population. Methods. A total of 33 patients with severe operative scoliosis, kyphoscoliosis, or kyphosis were studied based on hospital records, standing pretreatment, traction ( before anterior/posterior fusion), postoperative ( each stage), and final radiographs. Patients were analyzed by age at date of examination (range, 2-20 years; mean, 13.8 years), gender (18 male, 15 female), major coronal curve magnitude (range, 22degrees-158degrees; average, 84degrees), major compensatory coronal curve magnitude (range, 8degrees-123degrees; average, 51degrees), major sagittal curve magnitude (range, 13degrees-143degrees; average, 78degrees), traction protocol, and procedure type. Halo-traction-related, short- and long-term complications were noted in each case. Results. The major coronal curve reduced 38degrees or 46% after posterior spinal fusion compared to pretreatment radiographs. At an average of 44 months radiographic follow-up (range, 24-107 months), the loss of correction averaged 7degrees for major coronal curves and 4degrees of thoracic kyphosis. Clinical complications were noted in the perioperative and long-term time periods. Conclusions. The treatment of severe scoliosis can be very challenging despite the benefits of modern instrumentation methods, especially if there is a significant kyphosis or a history of intraspinal pathology. Halo-gravity traction is a safe, well-tolerated method of applying gradual, sustained traction to maximize postoperative correction in this difficult population. There were no permanent neurologic deficits in this series.