One hundred patients with 119 curves with idiopathic scoliosis, age ranged from 2 to 32 years, were-treated at Seoul National University Hospital from 1968 to 1979. Of 100 patients, 63 were adolescent type, 20 juvenile, and 17 infantile. The distribution of curve-patterns was 49 right thoracic, 19 double major (Rt. thoracic & Lt. lumbar), 18 left thoracic, 12 thoracolumbar, and 2 left lumbar. Of these patients, 67 with 83 curves were treated with Milwaukee-brace for one to seven years with an average of three and one-half years. Seven patients were treated surgically because of a poor response to the brace or progression of the curve.Sixteen patients with 20 curves followed for average 4. 6 years after the completion of brace treatment showed some loss of correction: 2.8 degrees for thoracolumbar, 3.1 degrees for thoracic, 4.2 degrees for lumbar segments and 4, 9 degrees for thoracic segments of double major curves. The brace was more effective for curves with 6 to 9 involved vertebrae and of less than 40 degrees. Thirty three patients with 36 curves were treated with Harrington instrumentation and posterior spinal fusion and followed from 1 to 12 years with an average of six and one-half years. The initial preoperative curves ranged from 50 to 120 degrees with an average of 75.3 degrees. Immediate postoperative correction ranged from 30 to 70 degrees with an average of 36. 2 degrees (48.1%). The average loss of correction at follow-up was 1.5 degrees (2.8%) for curves of less than 60degrees and 1.4 degrees (1.3%) for those of more than 101 degrees. Varioua methods of preoperative correction were applied. Halofemoral traction was applied for rigid and severe curve in 9 patients, Cotrel traction for less rigid one in 11 patients, Risser localizer cast for flexible one in 9 patients, and no preoperative correction for mild and flexible one in 4 patients.