Abstract: The use of immune checkpoint inhibitors (ICIs) is a revolutionary breakthrough in cancer treatment, which has changed the treatment modality for many types of tumors. The elderly account for the majority of cancer cases and deaths. There are some factors that may affect the treatment of ICIs in aging patients, such as immunosenescence, high incidence of autoimmune diseases and infectious diseases, and difference of tumor mutational burden from young patients. In most clinical trials of ICIs, aging patients did not account for the due proportion of the participants. Results of subgroup analysis and meta-analysis showed that age had little effect on the efficacy of ICIs and immune-related adverse events. Clinicians can refer to the relevant trial data and administer ICIs in elderly cancer patients with good physical condition to accumulate more real-world data.