In a retrospective study the authors had compared the results obtained in two series of identical scoliosis. All were examined after a two year minimal follow-up. Group A. There were 31 children operated on between 1966 and 1972. The average initial curve measured 111 degrees, and the average follow-up was eight years. In this group there was no preoperative preparation, and a Harrington rod was accompanied by cancellous grafting. The average correction was 34 degrees. Four paraplegias were seen, three of which recovered. Group B. There were 45 children operated on between 1973 and 1980. The average initial curve was 170 degrees and the average follow-up was 4.5 years. In this group, there was pre-operative use of a Halo cast routinely. In 14 children, Harrington rodding was supplemented by anterior fusion to correct associated kyphosis. The posterior Harrington rodding was completed by tibial grafting. The average correction was 47 degrees, without any neurological complications. It was noted that after one year, pulmonary function was not impaired to a greater extent after an anterior fusion than after a purely posterior fusion. Two-thirds of the cases gained considerable cosmetic benefit.