A 79-year-old man was admitted to our hospital for a close examination of an abnormal shadow on a routine chest roentgenogram. A large tumorous shadow in the right S1 segment, and hilar and mediastinal node swelling were observed. Transbronchial biopsy revealed that the histologic type of the tumor was oat cell carcinoma. The clinical stage was considered to be limited disease. Because of his age, 79 years, he was treated with VM26 as a single agent. VM26 was administered by intravenous drip infusion of 60 mg/m2 daily for five consecutive days every three to four weeks. After the third course of treatment with VM26, he achieved partial response, and then radiation therapy to the primary site and the hilar and mediastinal nodes was given at a total dose of 6,000 rad. There have been few phase II studies of VM26 in patients with small cell lung cancer (SCLC). Further phase II studies should be conducted for confirmation of the reproducibility of the phase II study of VM26 in SCLC, and the efficacy of combination chemotherapy including VM26 against SCLC should also be tested.