Early-onset scoliosis (EOS) presents a significant challenge, requiring effective deformity correction while preserving spinal and thoracic cage growth. Long-term follow-up studies have demonstrated that early spinal fusion is associated with reduced trunk height, restrictive lung disease, and increased mortality. This study aimed to evaluate the radiological outcomes, spinal growth, and complications associated with traditional dual growing rod (TGR) in EOS patients. Patients with EOS who underwent TGR at a single tertiary centre were retrospectively reviewed. Inclusion criteria were primary dual growing rod constructs with a minimum of two years of postoperative follow-up. Planned lengthening procedures were performed at six-month intervals following index surgery, with each distraction targeting 6 mm of controlled lengthening in accordance with physiological spinal growth rates. Radiographic parameters assessed included major Cobb angle, T1–T12 length, T1–S1 length, instrumented length, and space available for lung (SAL) ratio. Complications were recorded. Thirty-five EOS patients with average of 5.3 ± 3.0 TGR distractions were included. The mean preoperative major Cobb angle was 93.8° ± 21.9°, improving to 54.9° ± 14.6° immediate postoperative and 46.6° ± 10.1° at final follow-up (53% correction rate). Significant increase in spinal growth was observed, with mean T1–S1 length increasing from 282.1 ± 42.9 mm preoperatively to 372.6 ± 38.3 mm at final follow-up in patients undergoing ongoing distraction. Thoracic length (T1–T12) increased from 163.9 ± 33.7 mm to 216.6 ± 29.1 mm. Postoperatively, both concave and convex SAL measurements improved, with the SAL ratio increasing from 88.1% ± 8.5% to 94.7% ± 5.2%. Implant-related complications occurred in 34% of patients, while surgical site infection occurred in 6%. Proximal junctional kyphosis and rod breakage were the most common mechanical complications. TGR remain a cornerstone of EOS management by providing effective deformity correction and preserving spinal and thoracic growth. However, the persistence of implant-related complications underscores the importance of meticulous surgical dissection, avoidance of over-distraction and reinforcement of the proximal foundation (longer screws, sublaminar augmentation, and cross-links) to mitigate junctional stress and improve construct stability.