We observed a very rare case of primary lung cancer producing alpha-fetoprotein (AFP). A 70-year-old male with a history of smoking 50 packs per year was diagnosed with large cell carcinoma of the lung. The clinical stage was T2bN3M0 (IIIB), and serum AFP was 23,247 ng/mL. There was no evidence of metastasis to the liver, scrotum or other organs. While undergoing chemotherapy for 1 year, as the cancer progressed the AFP value steadily increased. The patient died of respiratory failure due to pneumonia 12 months after being diagnosed with lung cancer.