Nasopharyngeal oxygen (NPO) therapy is an emerging alternative to conventional face mask oxygen administration. It warrants consideration for treating hypoxaemia when face mask therapy is impractical or when patient intolerance or non-compliance regularly interrupt treatment. The effectiveness of the NPO route has been validated in post anaesthetic care and paediatric intensive care units (PICUs), but use in the adult ICU remains minimal. Recent research in the adult ICU setting has shown the nasopharyngeal route to be as effective as face mask oxygen administration in alleviating mild to moderate hypoxaemia, and is significantly more comfortable for patients. Therefore, NPO, administered via a fine catheter advanced into the nasopharynx, should be considered when face masks (FMs) or nasal prongs (NPs) are impractical or poorly tolerated and, because of its effectiveness and improved comfort, in patients for whom traditional non-invasive oxygen therapy is indicated. Implications for resource utilisation and costs also exist.