Docetaxel and gemcitabine combination chemotherapy has been reported to be active against non-small cell lung cancer (NSCLC) and myelosuppression is the most common dose-limiting toxicity. This prospective phase II study was designed to test the hypothesis that better tolerance and increased dose intensity might be achieved if patients are treated with weekly administration schedule. Thirty-five patients with stage IIIB/IV NSCLC and a performance status 0-2 received first-line chemotherapy with docetaxel 35mg/m2 and gemcitabine 600mg/m2 on days 1, 8 and 15. Treatment was repeated every 4 weeks, for up to 4 cycles. In total, 85 chemotherapy cycles were given (median, 2; range, 1-4). Other than the completion of all 4 planned cycles (n=6), the main reasons for treatment discontinuation were toxicity (n=15) and progressive disease (n=14). The most frequently encountered toxic effects were anemia (52% of patients), nausea and vomiting (60%), fatigue (71%) and anorexia (57%). One patient died of bilateral pneumonitis, which developed shortly after the administration of second cycle. Disease control (objective response and stable disease) in the intent-to-treat (ITT) population was achieved in 60% of patients and the overall response rate was 29% (95% CI, 14-44%). With a median follow-up duration of 13 months, the median progression-free survival and overall survival were 2.8 (95% CI, 0.7-4.8) months and 10.6 (95% CI, 7.0-14.3) months, respectively. In conclusion, weekly schedule of docetaxel and gemcitabine has modest activity with acceptable toxicity profile in advanced NSCLC, but as high frequency of early discontinuation occurred does not merit further study with the present regimen.