Study Design. A study of the results of surgical correction for patients with idiopathic scoliosis treated with either Harrington distraction rods with sublaminar wiring and Isola spinal instrumentation.Objectives. To provide data that directly compares the effectiveness of both systems, whether one system is inherently safer or more effective than the other in surgical correction of idiopathic scoliosis.Summary Of Background Data. Goals of surgery for idiopathic scoliosis include prevention of curve progression by obtaining a solid fusion as well as curve correction, restoration of trunk balance and maintenance of sagittal contour. Over sometime lack of understanding of the three dimensional nature of the deformity led adverse effects of distraction instrumentation. Since the era of Harrington’s instrumentation there have been many innovations in spinal instrumentation, mostly related to improved biomechanical profiles resulting in enhanced stability provided by the internal fixation systems leading to better results for surgical correction of scoliotic deformities. Methods. Clinical and radiological parameters were measured pre and postoperative for thirty patients in each group treated with Harrington instrumentation with sublaminar wiring or Isola instrumentation group and results analysed for comparison. Conclusion. Results of Isola instrumentation was shown to be superior achieving better correction of the deformity and better maintenance of correction under conditions of reduced postoperative immobilisation.