Purpose <p>This review aimed to highlight the association between upper airways dimensions and pediatric obstructive sleep-disordered breathing (oSDB).</p> Methods <p>We conducted a systematic review and meta-analysis of the published literature on upper airways dimensions in oSDB children compared with controls. We examined publications focusing on children aged up to 9 years old whose oSDB diagnosis was based on polysomnographic exams, identification of mouth breathing rather than normal nasal breathing, or snoring. To be included, these publications should evaluate differences in mean values of upper airways dimensions between oSDB children and controls. The risk of bias and certainty of evidence were assessed. This review followed the protocols recommended by the Preferred Reporting Items for a Systematic Review and Meta-analysis (PRISMA-2020) guidelines.</p> Results <p>17 studies were selected identified from the initial 489 publications identified. Children with oSDB symptoms showed a reduced cross-sectional area of the global airway and its nasopharyngeal and oropharyngeal subsections, a smaller minimum cross-section, and a shorter anteroposterior dimension of the upper part of the pharynx compared with controls, whatever the method used to image the upper airways. All the included studies were considered at low risk of bias even though some limitations were noted.</p> Conclusion <p>These findings have clinical implications as they help facilitate diagnosis and treatment of children with oSDB. More specifically, they indicate that the management of the pathology should focus on increasing the nasopharyngeal space and strongly support early adeno-/tonsillectomy as the primary treatment option in pediatric oSDB.</p>