Nowadays we have novel therapies for advanced stage non-small cell lung cancer. Immunotherapy has been introduced in the market for several years and until now its administration is mostly based on the programmed death-ligand 1. First line treatment with immunotherapy can be administered alone if programmed death-ligand 1 expression is ≥ 50%. All therapies for advanced stage disease have advantages and disadvantages, immunotherapy until now has presented mild adverse effects when compared to chemotherapy. However; it is known to induce inflammatory response to different tissues within the body. In our case acute pneumothorax was induced after immunotherapy administration.