Lung cancer, a leading cause of cancer-related mortality, disproportionately affects the elderly, who face unique challenges due to comorbidities and reduced organ function. Immune checkpoint inhibitors (ICIs) offer a more tolerable alternative to chemotherapy, but their efficacy and safety in elderly non-small cell lung cancer (NSCLC) patients remain underexplored due to limited representation in clinical trials. A narrative literature review was conducted using PubMed, Embase, and the Cochrane Library to evaluate studies on elderly NSCLC patients (≥65 years) treated with ICIs. Key outcomes assessed included overall survival, progression-free survival, response rates, treatment-related adverse events, and the influence of immunosenescence on treatment efficacy. The review highlighted evidence supporting the efficacy and safety of ICIs in elderly NSCLC patients, particularly those with good performance status. Age-related immunosenescence may affect outcomes, emphasizing the need for individualized treatment. Limited data suggest ICIs alone may be preferable to chemo-immunotherapy for patients over 75 years. However, the exclusion of elderly patients from clinical trials and methodological limitations reduces the generalizability of these findings. ICIs hold promise for advanced NSCLC in older adults, but tailored approaches and greater elderly inclusion in trials are needed to optimize outcomes.