Between 1982 and 1987 we carried out a prospective randomized study to compare the effectiveness of high-dose half-body irradiation (HBI) (A), intensive combined chemotherapy (B), and local or locoregional radiotherapy (C) in the therapy of extended small cell lung carcinoma (SCLC). 99 patients with a histologically proved SCLC were assigned to the three therapeutic groups of series: A = 31 patients, B = 37 patients, C = 31 patients. The median survival period showed a statistically significant advantage (p less than 0.01) for the chemotherapy group (B = 46 weeks) versus the two radiotherapy groups (A = 19 weeks, C = 23 weeks). The survival after half a year, one year, and two years also gave a clear advantage for the chemotherapy group. No difference was found between the radiotherapy groups A and C. The high-dose HBI gave no improvement of the sad therapeutic situation for the extended SCLC.