Purpose <p>This study aimed to determine whether coronal sacral tilt in children with congenital lumbar hemivertebra represents a primary or secondary deformity.</p> Methods <p>We reviewed 87 pediatric patients with lumbar hemivertebrae treated between January 2009 and December 2022. After applying inclusion criteria, 35 patients were analyzed: all had single lumbar hemivertebra causing congenital scoliosis, underwent hemivertebra resection with two-level fixation, had more than two years of follow-up, and complete imaging data. Based on preoperative coronal sacral tilt angles, patients were categorized into normal (0°–5°), mild (5°–10°), or severe (&gt; 10°) groups. We collected data on gender, age, follow-up duration, primary curve angle, pelvic incidence and sacral tilt angle at various timepoints.</p> Results <p>Preoperative coronal sacral tilt angles differed significantly among groups: normal (2 ± 2°), mild (8 ± 2°), and severe (12 ± 2°). Immediately after surgery, angles improved to normal (2 ± 2°), mild (3 ± 2°), and severe (3 ± 2°). At 3 months, values were normal (2 ± 1°), mild (2 ± 1°), and severe (3 ± 2°). By 1 year, angles measured normal (2 ± 1°), mild (2 ± 2°), and severe (3 ± 1°). At final follow-up, angles were 2 ± 2°, 2 ± 1°, and 3 ± 2°, respectively. While preoperative differences were significant (<i>P</i> &lt; 0.05), no intergroup or intragroup differences were seen postoperatively (all <i>P</i> &gt; 0.05).</p> Conclusion <p>Hemivertebra resection effectively corrects coronal sacral tilt by addressing the primary curve. Correction was consistent across all severity groups and remained stable over time. Preoperative hemivertebra orientation always matched the direction of sacral tilt, supporting the view that sacral tilt is a compensatory deformity.</p> Level of evidence <p>Level IV.</p>