This study analyzes data comparing anterior and posterior selective instrumentation to determine the optimal surgical approach for Juvenile Idiopathic Scoliosis correction. Systematic Review and Meta-analysis. We consulted the databases MEDLINE, CENTRAL, LILACS, and Embase on January 20th, 2024. We included cohort, case-control, and clinical trial studies involving patients aged 21 or younger with Juvenile Idiopathic Scoliosis (JIS) treated with selective instrumentation, comparing anterior and posterior approaches. We excluded studies with combined anterior and posterior instrumentation, thoracoscopic-assisted approaches, and vertebral body tethering. We assessed the studies’ risk of bias using the Newcastle-Ottawa Scale. Our meta-analyses compared Cobb angle correction rates and secondary intra- and postoperative outcomes. The analysis included 15 cohort studies (928 patients) 514 underwent anterior instrumentation and 414 posterior instrumentation. No deaths occurred. The average operative time was 260.7 minutes for anterior and 190.4 minutes for posterior procedures. Average blood loss was 398.4 mL (anterior) and 413.4 mL (posterior). Cobb angle correction rates were 61.7% (anterior) and 66% (posterior). Meta-analyses revealed no significant differences in Cobb angle correction rates between groups (p = 0.774, 95% CI: -0.331 to 0.444; p = 0.365, 95% CI: -0.23 to 0.62). Anterior and posterior selective instrumentation achieve similar Cobb angle correction rates, and the choice for JIS in patients under 21 years remains highly individualized. Both approaches show comparable outcomes in correction, bleeding, and SRS-22 scores. Posterior instrumentation reduces operative time and hospital stays, while anterior instrumentation requires fewer instrumented vertebrae. The lack of clinical trials and incomplete outcome reporting may limit some analyses, though supplementary meta-analyses mitigated these constraints.