Introduction: Adolescent idiopathic scoliosis (AIS) surgeries are major paediatric procedures requiring multidisciplinary management. Enhanced recovery after surgery (ERAS) programs, with proven benefits in adults, remain poorly developed in paediatrics. The main objective of this Before/After study was to evaluate the impact of an ERAS program implementation for AIS on length of stay (LOS) and postoperative recovery. Methods: The ERAS protocol included intrathecal morphine, standardised multimodal analgesia and multidisciplinary measures for early recovery. Retrospective data from adolescents operated between 2015 and 2017 ("Before ERAS" group) were compared with data from patients benefiting from the ERAS program ("After ERAS" group). Patients treated for neuromuscular scoliosis were not included. After a descriptive analysis, a propensity score matching defined two comparable populations. The main outcome was the LOS. The time to first solid food intake, first ambulation, first bowel movement and Foley removal were also analysed. Results: During the "Before ERAS" period, 73 underwent PSF for AIS. Thereafter, 65 patients benefited from the ERAS protocol, including 35 for AIS. After propensity score application, 32 patients of the "After ERAS" group were matched with 32 patients of the "Before ERAS" group. The ERAS implementation was associated with 25% reduction in LOS (2.10 ± 1.60 days p < 0.001). All other enhanced recovery criteria were significantly reduced after ERAS implementation. Conclusion: These results confirm the expected benefits of ERAS program in AIS with a significant impact on postoperative recovery and LOS. Patient adherence and the involvement of all caregivers are essential to the success of such a program.