Forty-nine cases with small cell lung cancer (SCLC) treated with chemotherapy and radiotherapy were analyzed. Eight of them were of limited disease (LD), and 41(83.7%) had extensive disease (ED). Forty six were treated on a protocol comprising the induction with cyclophosphamide 1g i.v. on days 1st and 8th, vincristine 1-2mg, i.v. on days 1st and 8th, etoposide 100mg i.v. on days 3rd-7th and methotrexate 20mg i.v. on day 3rd, 5th, 9th, 11th and than repeated with the second course of treatment after 21 days. Eight patients (17.4%) responded completely. There were 29 cases with partial response (63%). The total response rate was therefore 80.4%. Then radiotherapy (50 GY Over 4 weeks) was administered to primary cancer area in 36 patients of good response. The CR was increased from 19.4% to 55.6%. Twenty patients had CR. These patients were treated by late intensification with average of six cycles. The median survival period was 10 months. 21 patients (58.3%) were alive more than 1yr. 10 patients (27.8%) survived more than 2 yrs. Six patients (24%) were alive more than 3 yrs. One patient survived over 7 yrs. It was suggested that combined therapy is important for achieving a better response. CR is beneficial for long term remission. Late intensification is a kind of treatment with minimal toxicity and longer remission. Metastases to the central nervous system usually caused death, so prophylactic CNS irradiation (PCI) should be used in patients with ED for achieving a longer remission.