This was an open-label randomized Phase III study of 207 patients with either unresectable or metastatic non-small cell lung cancer (NSCLC) who were treated with docetaxel plus best supportive care (BSC) or best supportive care alone. Patients in the chemotherapy arm of the study received docetaxel 100 mg/m(2) as a 1 h intravenous infusion every 21 days until they showed evidence of progressive disease, or estimated maximum benefit obtained or unacceptable side effects. Patients who received docetaxel were pretreated with oral dexamethasone. Patients in the BSC arm should not receive chemotherapy or anticancer therapy except for palliative radiotherapy. Overall survival obtained in the docetaxel arm was significantly longer than in the BSC arm (P=0.026). Two-year survival in the docetaxel arm was 12%, whereas none of the BSC patients survived after 20 months. The response rate was 13.1% (95% CI, 7.5-18.8%). There was a significantly longer time to progression in the docetaxel versus the BSC arm (P<0.001), and statistically significant improvement of clinical symptoms with docetaxel compared to BSC. The quality-of-life descriptors were in favor of docetaxel, and the difference was significant for pain, dyspnea and emotional functioning. The safety profile of docetaxel for this study was similar to that already reported in this patient population.