Abstract: Non-small cell lung cancer (NSCLC) is the most common form of lung cancer, and patients with advanced disease generally have a poor prognosis. In recent years, immune checkpoint inhibitors (ICIs) have been approved as first-line therapy for patients with NSCLC lacking actionable driver mutations. Emerging evidence indicates that ICIs reduce tumor burden in some patients and may affect pulmonary ventilation and diffusion capacity, which are associated with clinical outcomes. This review summarizes baseline pulmonary function characteristics in advanced NSCLC, outlines in the impact of ICI therapy on lung function, and discusses potential mechanisms through which immunotherapy can influence pulmonary function, with the aim of guiding lung function monitoring and individualized management during ICI treatment.