Purpose This study investigated the effects of Gyrotonic exercise (GE) on the Cobb angle and multidirectional trunk stabilization outcomes in adolescents with adolescent idiopathic scoliosis (AIS). Methods This randomized controlled trial included 26 adolescents with AIS who were randomly assigned to the GE group (n=13) or the ballandsling exercise (BSE) group (n=13). Both groups completed 1hour exercise sessions twice weekly for 12 weeks. The primary outcome was the Cobb angle, and the secondary outcomes were trunk stabilization moments measured in eight tilt directions using the CENTAUR device. Betweengroup differences in postintervention outcomes were assessed using analysis of covariance adjusted for baseline values. A Bonferronicorrected significance threshold of P<.00625 was applied to the eight secondary outcomes. Results All participants completed the study, and no adverse events were reported. The GE group demonstrated a significantly lower postintervention Cobb angle than the BSE group after baseline adjustment (P<.001; unadjusted Cohen's d=1.39). Significant betweengroup differences favoring GE were observed at 0° (P=.003), +90° (P<.001), +135° (P<.001), −135° (P=.001), and 180° (P=.002), based on the Bonferronicorrected significance threshold. Conclusion Compared with BSE, GE resulted in a lower short term Cobb angle and higher trunk stabilization moments in selected tilt directions in adolescents with AIS. These findings suggest that GE may be a useful adjunctive exercise intervention for improving short term radiographic Cobb angle and devicebased trunk stabilization outcomes.