Introduction: The most frequent type of spine abnormality throughout adolescence was adolescent idiopathic scoliosis (AIS). Hippotherapy improved posture, balance and gait of different musculoskeletal conditions. Therefore, this study aims to see how hippotherapy combined with Schroth exercises affected postural asymmetry and dynamic balance in AIS compared to traditional physiotherapy (Schroth exercises) alone. Materials and methods: In this randomized controlled trial, fifty-two patients with AIS (10–18 years, 37 girls and 15 boys) participated. They were arbitrarily allocated into two groups: experimental (19 female/8 male; aged 14.74 ± 1.79 years; Cobb angle 18.59 ± 2.66 degrees) and control (18 female/7 male; aged 15.04 ± 1.81 years; Cobb angle 19.32 ± 2.69 degrees) groups. Both groups received Schroth exercises for 10 weeks, three days/week. The experimental group additionally received hippotherapy training. Pre-treatment and post-treatment assessment for the scoliotic, kyphotic angle, pelvic obliquity, pelvic torsion and vertical spinal rotation and the anteroposterior, mediolateral and overall stability indices were assessed using the formetric system 4D and Biodex Balance System, respectively. Results: After intervention, both groups illustrated significant improvements in all examined variables (p < 0.05). The experimental group illustrated significant improvements in scoliotic angle, kyphotic angle, pelvic obliquity, pelvic torsion and vertical spinal rotation and the stability indices compared to the control group (p < 0.05). Conclusion: In adolescence idiopathic scoliosis, hippotherapy training combined with Schroth exercises improves posture asymmetry and balancing ability more effectively than Schroth exercises alone.