Introduction: Heated Humidified High Flow Nasal Cannulae (HHHFNC) therapy is widely used in the Paediatric Intensive Care Unit (PICU) at National Hospital – Galle as non-invasive respiratory support for children with respiratory distress and hypoxaemia. Proper setup, monitoring and timely troubleshooting are essential to prevent complications and avoid unnecessary escalation. This audit evaluated nursing officers’ knowledge regarding HHHFNC troubleshooting in accordance with international and institutional standards. Objectives: To assess knowledge of HHHFNC troubleshooting among PICU nursing officers,including identification of common problems, management of humidification and cannula fit issues, response to device alarms, and appropriate escalation of unresolved problems. Methods: A prospective, questionnaire-based clinical audit was conducted among all eligible PICU nursing officers (n=24) using total population sampling. A structured 12-item online questionnaire assessed knowledge across troubleshooting domains. Each correct response scored one point (maximum 12). Results were analysed as percentage correct per question and compared with the target standard of ≥90% correct knowledge in each domain. Results: The mean score was 10.9/12 (91%). Overall, 91.7% scored ≥80%. Standards were achieved incircuit disconnection, humidification, cannula fit and escalation domains (100%). Documentation (58.3%) and identification of common troubleshooting issues (58.3%) did not meet the ≥90% standard. Conclusions: PICU nursing officers demonstrated good overall knowledge of HHHFNC troubleshooting. Targeted education and re-audit in 3–6 months are recommended to achieve full compliance with audit standards.