From 1979 to 1982, 80 patients with unresectable non-mall-ell lung cancer without metastasis were treated with high-ose radiotherapy to the primary and to regional lymph nodes with or without supraclavicular lymphatic in the Department of Therapeutic radiology, Seoul National University Hospital. Of these, 56 patients (70%) were completely evaluable, and 59 patients (74%) had squamous cell carcinoma, 13% large cell undifferentiated carcinoma and 8% Aden carcinoma. 21 patients (26%) had Stage II and 59 patients (74%) had Stage III. The complete and partial response rate in the high-ose (~ 6,000rad) radiotherapy was 70% with 19% complete response. 69 patients (86%) failed in the treatment, by the failure pattern, 64% had local failure alone, 35% had local failure and distant metastasis and 1% had distant metastasis alone. The failure rate in the thorax was 76% in squamous cell carcinoma, 40% in Aden carcinoma and 20% in large cell undifferentiated carcinoma. Preliminary result shows that actuarial survival at 1, 2 and 3 years were 56%, 26% and 20% in overall patients and 64%, 37% and 21% in Stage II and 54%, 21% and 18% in Stage III, respectively. Overall median survival was 14 months; 17 months in Stage II and 13 months in Stage III. 8 patients (10%) have lived a minimum of 2 years with no evidence of disease. There was no fatal complication confirmed to be induced by radiotherapy, so definitive high-ose radiotherapy was tolerated well without major problems and resulted in good local control and survival.