Objective: To summarise our experience and the outcomes of endoscopic balloon dilatation (EBD) in the management of paediatric-acquired subglottic stenosis (SGS), and to further explore the influencing factors of successful EBD. Method: A retrospective case series study was conducted involving 33 paediatric patients diagnosed with acquired SGS who underwent EBD as the primary treatment from January 2012 to December 2021. The collected information included patient demographics, aetiology, time from extubation to operation, initial grade of SGS, descriptions of stenosis tissues, presence of tracheotomy, number of dilatation procedures and co-morbidity. The follow-up results were collected and analysed. Result: Thirty-three paediatric patients with an average age of 31.0 months who underwent EBD were included in the study. According to the Myers-Cotton classification, four (12.1%) patients had Grade I stenosis, nine (27.3%) had Grade II, 20 (60.6%) had Grade III and none had Grade IV. Of these, 15 (45.5%) exhibited acute lesions and 18 (54.5%) exhibited chronic lesions. The mean number of dilatation procedures per patient was 1.88 +/- 1.05, and 19 (57.6%) patients received dilatations more than once. The overall success rate was 72.7%, with 100% for Grade I, 88.9% for Grade II and 60.0% for Grade III. There was a significant difference between the distribution of the stenosis grades in the successful and failed cases (p < 0.05). The mean number of dilatation procedures was 1.47 +/- 0.64 and 2.22 +/- 1.22 per patient in those with acute lesions and chronic lesions, respectively. The patients with chronic lesions had a significantly higher number of dilatations than those with acute lesions (p < 0.05). The success rate was 86.7% for acute lesions and 61.1% for chronic lesions. The correlation between the type of subglottic lesions and procedural success was not statistically significant (p > 0.05). Conclusion: Acquired SGS in paediatric patients can be successfully managed using EBD. The dilatation procedures should be performed in a timely manner, early treatment could prevent the need for multiple procedures and smaller stenosis grades could improve the success rate of the surgery. (c) 2023 Japanese Society of Otorhinolaryngology-Head and Neck Surgery, Inc. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license(http://creativecommons.org/licenses/by-nc-nd/4.0/)