Lung cancer is the leading cause of cancer-related deaths worldwide. Although improvement has been achieved in platinum-based chemotherapy and tyrosine kinase inhibitors-based molecular targeted therapy, they still have limitations. Immunotherapy has recently emerged as a very effective new treatment, and there is now growing enthusiasm in cancer immunotherapy worldwide. We summarized the effects of immune checkpoint inhibitors in clinical trials, and the current status and progress of anti programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) agents in lung cancer treatment. Attention has been paid to finding out the factors which influence the therapeutic effect of anti-PD-1/PD-L1 therapy and reducing the occurrence of adverse events.