OBJECTIVE Small cell lung cancer is sensitive to chemotherapy and radiotherapy. Nevertheless, responses are still short-lived and apparent cure remains for only limited disease patients. METHODS We combined cyclophosphamide (750 mg/m2 by intravenous infusion at first day) vincristine (2 mg intravenously at third day), cisplatin (20 mg/m2 intravenously for 3 days), and etoposide (100 mg/m2 intravenously for 3 days) with radiotherapy (total 300cGy over 4 weeks in 17 fractions) and treated 39 patients with small cell lung cancer who had received no prior systemic chemotherapy and radiotherapy. RESULTS 1) Thirty-nine patients (limited disease: 17 patients, extensive disease 22 patients) were treated and 35 patients were evaluable for response. Overall response rate was 82.8% (complete response 28.6%, partial response 54.2%). 2) The median survival was 52 weeks for all patients and 58 weeks for limited disease and 45 weeks for extensive disease. There was no statically significant survival difference between the two patient groups. The median relapse-free survival time was 48 weeks. 3) Overall, treatment was well tolerated, with granulocytopenia being the most frequent toxicity. CONCLUSIONS Combination chemotherapy with COPE regimen combined with radiation therapy was effective as a first line therapy for SCLC.