Objective: Early-onset scoliosis (EOS) poses a significant therapeutic dilemma, as progressive spinal curvature during early growth can compromise thoracic development and pulmonary function. The growing-rod domino technique has emerged as an important surgical strategy, allowing serial deformity correction while preserving spinal growth and reducing the need for repeated surgical interventions. Methods: We report a technical case study of a 9-year-old girl with idiopathic EOS who presented with a right thoracic Cobb angle of 107° and a compensatory lumbar curve of 62°, Risser stage 0, and a restrictive pulmonary pattern (forced vital capacity 72% predicted). Under general anesthesia with continuous neurophysiological monitoring, rod constructs were anchored proximally at T2–4 and distally at L3–4 using unilateral pedicle screws. The rods were contoured to maintain sagittal balance and tunneled submuscularly. A 20-mm intraoperative distraction was performed. Postoperative management included early mobilization, outpatient magnetic lengthening, and serial radiographic assessments. Results: Intraoperative distraction reduced the thoracic and lumbar curves to 42° and 20°, respectively, with stable somatosensory evoked potential and motor evoked potential signals maintained throughout the procedure. The patient was extubated without complications, mobilized on postoperative day 2, and discharged on postoperative day 4. At 6-month follow-up, outpatient growing-rod activations achieved an additional 5 mm of spinal length. Radiographs confirmed sustained deformity correction, preserved spinal growth, and intact instrumentation. No perioperative or follow-up complications, including infection, implant failure, or autofusion, were observed. Clinically, the patient demonstrated improved trunk symmetry and respiratory function. Conclusion Growing-rod constructs using the domino technique provide a safe, effective, and patient-centered approach for the management of severe EOS. By achieving meaningful deformity correction while allowing continued spinal growth and reducing overall surgical burden, the growing-rod domino technique represents a valuable treatment option in skeletally immature patients, enabling deferral of definitive fusion until skeletal maturity.