1. The natural history and prognosis of progressive infantile idiopathic scoliosis are reviewed and twenty-eight cases are reported.

2. Resolving infantile idiopathic scoliosis is described and seven cases are reported.

3. The length of the curve, the degree of rotation, the age of onset of deterioration, and the rate of progression are the important factors in determining the type and severity of the deformity.

4. Infantile idiopathic scoliosis is briefly compared with congenital scoliosis.