Docetaxel is a novel, potentially highly beneficial drug for the treatment of lung cancer, and has shown remarkable radio-sensitizing effects in vitro. In the present study, we evaluated whether weekly docetaxel (20 mg/m(2)) and conventionally fractionated radiotherapy with the two-dimensional (2D) technique could be tolerated and effective in the treatment of locally advanced non-small-cell lung cancer (NSCLC). Thirty-two stage III (IIIA:13, IIIB:19) NSCLC patients were treated with weekly administration of docetaxel (20 mg/m(2)) on days 1, 8, 15, 22, 29 and 36 in addition to concurrent radiation therapy. The total tumor dose was 60-66 Gy given with a 2D technique in 6-7 weeks. Complete response was observed in 9/32 (28%) patients and partial response in 20/32 (63%). Three (9%) patients died of chemoradiation-induced pneumonitis after completion of therapy. In total, grade >3 toxicities included pneumonitis (47%) and esophagitis (16%). The median overall survival duration was 12 months. The dimensions of the radiotherapy port were larger in patients who produced severe (grade >3) chemoradiation pneumonitis than in patients who did not (P<0.05). The median survival time was 12.4 months and 2-year overall survival were 35%. The survival was better in patients whose first radiotherapy port dimensions were less than 150 cm(2) compared to patients whose first radiation port dimensions were >==150 cm(2) (P<0.05). In conclusion, concurrent weekly administration of docetaxel (20 mg/m(2)) with 2D radiotherapy for NSCLC, had good local response, but survival rate was not completely satisfactory due to chemoradiation pneumonitis, which was the principal toxicity that adversely affected prognosis in elderly patients whose radiotherapy port was large.