Carcinosarcoma is the group of neoplasms possessing both carcinomatous parenchyma and sarcomatous stroma. These tumors are relatively uncommon and may arise in variable organs. In this case, a 62-year-old male patient was admitted to our department due to left chest pain and general weakness of three months duration. The chest x-ray revealed egg-sized, relatively well defined lobulated soft tissue mass in left paracardiac area. Left lower lobectomy was performed under the preoperative impression of lung cancer. Pathologic examination of the resected lung revealed carcinosarcoma without regional lymph node metastasis. Patient is doing well at present without any chemotherapy.