The purpose of this paper is to study the effect of applying a postoperative rather than a preoperative correctional plaster in cases of scoliosis. This has advantages in that it shortens the period of hospitalization, the patient is more comfortable, and surgery is easier without the jacket. Seventy patients were so studied. In 68 of these, a preoperative test correction was compared with the final immediate postoperative correction in plaster. This was done to compare the correction that would have been obtained with the actual correction obtained. They were found to be essentially the same. Forty-four of these patients were followed from 1 to 3 years and the end-result was evaluated. The average initial correction was 45% of their preoperative erect curve. The average maintained correction, however, was 30%.