We evaluated the cases of 222 patients older than twenty years in whom scoliosis was the primary diagnosis. No patient had had prior surgical treatment. The diagnoses were idiopathic scoliosis in 160 patients, paralytic scoliosis in forty-four, and congenital scoliosis in eleven, and there were miscellaneous diagnoses in seven patients. The average age of the patients when first seen was 30.7 years. The indications for operation were pain, progression of the curve, magnitude of the curve, and cardiopulmonary symptoms. Preoperative traction, including halo-femoral traction, did not result in increased correction when compared with the initial supine side-bending roentgenogram. A one-stage fusion was performed in 174 patients and multiple-stage procedures, in forty-eight patients. At an average follow-up of 3.6 years the average loss of correction was 6.2 degrees, 68 per cent of the patients were free of pain, and a solid fusion had been obtained in all but six patients. Complications developed in 53 per cent of the patients, the most common problems being pseudarthrosis, urinary tract infection, wound infection, instrumentation problems, a pulmonary disorder, and loss of lumbar lordosis. Paraplegia occurred in one patient. The over-all mortality rate was 1.4 per cent. Complications increased with age, and the highest mortality rate was in patients with congenital scoliosis who had cor pulmonale.