Surgical intervention for adolescent idiopathic scoliosis (AIS) should be proven to alter the natural history without introducing iatrogenic complications. The risks of surgery should be substantiated by a body of scientific research, which should show a clear superiority of surgery over observation, both in the short term and the long term. The purpose of this review was to conduct a systematic search of the literature to critically evaluate the scientific evidence on the long-term outcomes and complications of surgical intervention for AIS. Our search identified 39 distinct patient populations with a minimum average follow-up of 5 years. No long-term, prospective controlled studies exist to support the hypothesis that surgical intervention for AIS is superior to natural history. Although surgery reliably arrests the progression of deformity, achieves permanent correction, and improves appearance, there is no medical necessity for surgery based on the current body of literature. However, the surgeon must not underestimate the psychological indication that occurs when a patient is no longer able to cope with the deformity.