A 70-year-old man was referred to our hospital for an abnormal chest X-ray shadow. A chest CT scan showed a mass shadow with a cavitary lesion in segment 6 of the right lung. One year after radical resection(resection of the lower lobe of the right lung; pT2aN0M0, pStage ⅠB), the patient exhibited enlarged mediastinal lymph nodes and liver metastases, and postoperative recurrence was determined. After treatment with the immune checkpoint inhibitors nivolumab(Nivo)and ipilimumab(Ipi), the mediastinal lymph nodes and liver metastatic lesions shrunk markedly, and a complete response was achieved. The complete response persisted for over 21 months after treatment cessation and 30 months after starting treatment. Therefore, Nivo/Ipi therapy is useful for metastatic pulmonary pleomorphic carcinoma with low programmed cell death ligand-1 expression.