Between March 1992 and February 1993, hyperfractionated radiotherapy (HRT) (1.2 Gy.fraction-1, twice a day, total dosage of 69.6 Gy) and simultaneous cisplatin (70 mg.m-2, 3rd and 23rd days of HRT) and etoposide (70 mg.m-2, 1-3rd and 20-23rd days of HRT) were applied to 27 patients with inoperable non-small cell lung cancer (NSCLC). Their Karnofsky performance statuses were 70-90%, and mean age was 52 (36-63). Two cases were stage II (one of the patients refused the operation and the other was medically inoperable because of insufficient ventilation), eight were stage IIIA and 17 were stage IIIB. No severe life-threatening grade IV acute toxicity findings were observed. Generally, acute side-effects were transient and did not require discontinuation of treatment. Tumour responses were as follows: complete response in six cases (23%); partial response in 19 cases (70%); and stable disease in two (7%). When complete response rates were compared according to stage, histological type, age group and weight loss, no statistically significant difference was found. Median overall and disease-free survival times were 14 months (95% confidence interval) (95% CI) 11-17 months and 10 months (95% CI 7-13 months), respectively. Twelve and 24 months overall and disease-free survival rates were 56 and 30%, and 36 and 24% respectively. No statistically significant difference was found in overall survival rates among epidermoid and nonepidermoid types, while the difference in disease-free survival was statistically significant. The acute and late complications of our HRT and simultaneous chemotherapy protocol were tolerable and the survival rates were encouraging.