The goal of this study is to test the hypothesis that physiotherapy-based intervention can reduce incidence of progression in children with IS. Two independent patient groups matched by age and sex at diagnosis were analysed using the outcome parameter, incidence of progression (> or =5 degrees ). One group was untreated and the other received scoliosis in-patient rehabilitation (SIR). Incidence of progression in groups of untreated patients ranged from 1.5-fold (71.2% vs 46.7%) to 2.9-fold (55.8% vs 19.2%) higher than in groups of patients treated with SIR, even when SIR-treated groups included patients with more severe curvatures. Statistically, the differences were highly significant. Efforts to test the hypothesis that physical therapies addressing postural imbalance can be used effectively in the treatment of IS have been limited. The results of this study are consistent with the possibility that a supervized programme of exercise-based therapies can reduce incidence of progression in children with IS.