The effective treatment of adolescent idiopathic scoliosis (AIS) is predicted on timely detection and appropriate intervention. School screening programs have resulted in a reduced incidence of advanced curvature upon referral. Studies of the natural history of AIS demonstrate that a number of factors are of predictive value in assigning risk for progressive curvature and subsequent deformity and/or morbidity. These are age at time of diagnosis, stage of skeletal maturity, and magnitude and pattern of curvature. The options in treating AIS are observation, orthosis, and operation. Spinal orthoses are designed to arrest the progression of curvature during skeletal maturation. Newer brace designs and protocols facilitate compliance with long-term bracing and may reduce the incidence of curves requiring operative intervention. The goal in scoliosis surgery is to reduce curvature and to create a stable framework on which vertebral fusion can occur. Technical advances have yielded a number of instrumentation options for achieving this goal. Basic technical comparisons are made among of prototypes of posterior spinal instrumentation. The newest of these, Cotrel-Dubousset, may supplant Harrington rod instrumentation as the preferred standard in the operative treatment of AIS.