High-flow nasal cannula (HFNC) is a noninvasive respiratory support system that delivers heated (31-38℃), humidified (100%), and oxygen-enriched air at a constant high flow rate (15-60 L/min). Due to its numerous physiological benefits, with added convenience and minimal side effects, HFNC has been increasingly used in patients with acute hypoxemic respiratory failure over the past decade. However, the clinical benefits of long-term HFNC remain uncertain. Several studies, though, suggest its potential use as an alternative home oxygen therapy for patients with chronic stable lung diseases such as chronic obstructive pulmonary disease (COPD), interstitial lung disease, and bronchiectasis. The use of long-term home HFNC in patients with chronic respiratory failure is an emerging area with promising potential. Despite limited clinical research, this narrative review aims to describe the physiology of HFNC use and summarize the current evidence on its long-term application. It provides healthcare providers with insights and perspectives on the potential role of long-term home HFNC.