Traditionally, lung cancer has been treated as an immune-resistant disease with platinum-based chemotherapy serving as the first-line treatment for metastatic disease. The efficacy of immunotherapy has been established for patients with advanced lung cancer in clinical trials, and it has since become the standard of care for patients without targetable mutations, with or without chemotherapy. Previously, lung cancer patients experienced limited responses to immune-based therapy. As clinical trials continued to explore immunotherapy options with checkpoint inhibitors, results showed that immune therapies can create durable responses with manageable toxicities. Patients with advanced non-small cell lung cancer (NSCLC) can experience improved survival when administered immunotherapy over chemotherapy. The first successful immunotherapy treatments developed exploit programmed death 1/programmed death ligand 1 (PD-1/PD-L1) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), immune checkpoint pathways. Combination therapies of PD-1/PD-L1 inhibitors and chemotherapy or PD-1/PD-L1 and CTLA-4 checkpoint pathway inhibitors have also demonstrated improved outcomes for patients with NSCLC. Combination therapy with PD-1 or PD-L1 therapy and chemotherapy has shown benefit for small cell lung cancer patients as well. As immunotherapy changes the treatment paradigm of lung cancer, researchers continue to investigate different combinations, timing, duration, and biomarkers to better understand and improve the efficacy of immune-based therapy for patients with lung cancer.Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.