In this study, we applied an alternating non-cross resistant combination chemotherapy to 17 patients with small cell lung cancer. Cyclophosphamide, Methotrexate, and CCNU were given for the first 6 weeks. After the 12 weeks of chemotherapy, prophylactic cranial irradiation was applied to 6 patients who had appropriate social-economic conditions. The response rates were evaluated excluding 4 patients who were administered adjuvant chemotherapy. We achieved 4 complete remissions (CR), and 7 partial remissi CR + PR) was 84,6 %. Median survival was 11 months for limited disease and 8 months for the patients with extensive disease. Two patients died because of thrombocytopenia and leukopenia during chemotherapy. The response rates achieved in this study are not superior to the results of three- or four-drug combination chemotherapies. On the other hand, our treatment is more toxic and less tolerable.