We report 2 cases of pulmonary pleomorphic carcinoma. The patient in case 1 was a 44-year-old man who was admitted to our hospital complaining of dry cough and dyspnea on exertion. Chest radiography and CT showed a huge tumor with left pleural effusion. Percutaneous biopsy suggested malignancy. As distant metastasis was not found and as cytological examination of pleural effusion gave a result of class II, we attempted to perform left pneumonectomy. However, we performed partial resection of the tumor because it had invaded the aorta, pulmonary artery, pericardium and pleura. The pathological diagnosis was pleomorphic carcinoma, p-T4 N2 M0. After the operation, we performed systemic chemotherapy, including cisplatin and irinotecanm with little effect (PD). The patient died of progression of the tumor. Case 2 was a 34-year-old man who was admitted to our hospital complaining of fever and general malaise. Chest radiography and CT showed a tumor in the left upper lobe. As no distant metastasis was found, we tried left upper lobectomy. However, we performed left upper segmentectomy and lymph node dissection because of invasion of the aorta and the chest wall, and because of hypersegmentation of the left upper lobe. Pathological diagnosis was pleomorphic carcinoma, p-T4 N0 M0. After the operation, the mediastinum was subjected to radiation therapy. However, a metastatic tumor was found in the pelvis after this radiation was given. We performed systemic chemotherapy with substances including cisplatin, gemcitabine and vinorelbine, but with little effect (PD). The patient died of peritonitis and pleuritis due to the recurrence and progression of the tumor. Both cases had rapidly growing neoplasms showing little sensitivity to chemotherapy or radiotherapy. Pulmonary pleomorphic carcinoma is suggested to be type of lung cancer with a poor prognosis when the tumor is not resected in the early stages.