AIMS Paediatric subperiosteal orbital abscesses (SPOA) are a serious suppurative complication of rhinosinusitis, requiring prompt diagnosis and timely management. This study reviews subperiosteal and orbital abscess presentation and management trends over a 20-year period at a tertiary paediatric referral hospital. METHODS A retrospective review of children diagnosed with Chandler stage III-V orbital cellulitis requiring surgical intervention from 2005-2024 at Sydney Children’s Hospital was conducted. Data included demographics, clinical presentation, treatment, pathogens, and outcomes. Surgical intervention included tailored endoscopic sinus surgery (middle meatal antrostomy, ethmoidectomy ± medial orbital decompression) and open surgery (transcaruncular, transconjunctival, lid crease, or brow incision). RESULTS Eighty-seven patients (mean age 9.1±4.0 years; 63.2% male) were included. 73.6% were transferred from peripheral hospitals and 57.5% had right-sided involvement. 91.2% presented with Chandler III orbital cellulitis, mean WCC 16.0±5.5 x10^9 cells/L and CRP 96±82.6 mg/L. There was a significant increase in incidence and severity of subperiosteal and orbital abscesses over the last 20 years, with 42.5% of presentations occurring within the last 5 years. Surgical intervention occurred on average within 24 hours of admission. 51 patients (58.6%) had a combined endoscopic/open approach, 28 (32.1%) endoscopic only, and 15 (17.2%) open only. Eight patients (9.1%) needed a second surgery for disease control. Identified pathogens included strep. milleri (26%), strep. pyogenes (15%) and strep. pneumoniae (7%). The median hospital stay was 7.8±6.4 days and 8% required ICU admission. CONCLUSION Over the last 20 years, the prevalence and severity of SPOA has notably increased. Children can be safely managed with combination IV antibiotics, steroids, and surgical intervention - whether endoscopic, open, or combined. Insights from this research will help direct ongoing SPOA management paradigms.