Conservative treatment of idiopathic scoliosis is more effective as a result of early diagnosis in conjunction with the use of specific physiotherapy and bracing techniques. Our aim was to investigate the effectiveness of specific physiotherapy developed according to the concept of spinal reflex balance using the GraviSpine device. This study is a retrospective analysis of prospectively collected data. A total of 199 patients aged 6-17 years, with a mean age of 11.26 ± 3.35 years, including 168 girls (84.4%) and 31 boys (15.6%), out of a total of 830 patients treated for IS at the Scoliosis Treatment Center in 2014-2019 were included in the assessment, which was conducted according to the inclusion and exclusion criteria. The study group was divided into three age groups. Group A subjects were 6-9 years old; group B, 10-12 years old; and group C, 13-17 years old. The mean follow-up time was 28.71 ± 10.98 months. Treatment outcomes were compared, based on changes in the Cobb angle and the angle of trunk rotation before and after treatment, both within the groups and with respect to sex and curvature location, using the Wilcoxon signed-rank test. Cobb angle changes in patients were classified as improvements, stabilizations, or deteriorations according to the SOSORT criteria. A majority of patients improved or stabilized after treatment, with 67%, 71%, and 90% of subjects in groups A, B, and C, respectively, achieving these results. In group C (the oldest children), a statistically significant reduction of -1.84° ± 6.88° (6.31%) in the mean Cobb angle was achieved after treatment. With regard to sex, improvements and stabilizations accounted for 81% of cases in girls and 61% in boys, respectively. With respect to location, statistically significant reductions in the Cobb angle were noted for thoracic and thoracolumbar spines of -2.2° ± 7.54° (10.17%) = 0.022 and -2.2° ± 6.58° (6.36%) = 0.049, respectively. A significant reduction in the mean angle of trunk rotation was obtained in the group and in three curvature locations. Based on the presented research findings, the utilization of the GraviSpine device as an adjunct to specific PSSE (physiotherapeutic scoliosis-specific exercises) physiotherapy and bracing in the management of pediatric patients with mild to moderate scoliosis appears to enhance treatment efficacy.