Effective control of severe immune-related adverse events, including cytokine release syndrome (CRS), is essential for the success of immunotherapy. We present a case of a granulocyte colony-stimulating factor-producing pleomorphic lung carcinoma treated with nivolumab plus ipilimumab which developed CRS and severe immune-related pneumonitis. The effect of immunotherapy was heterogeneous; gastric metastasis was eliminated, but the pulmonary lesion had primary resistance. Steroid and tocilizumab were successful in controlling CRS, but additional infliximab was necessary to control pneumonitis. To control immune-related adverse events, it is important to choose immunosuppressive agents to the specific target organ and inflammatory cells.