We performed a Phase II trial to evaluate the activity and tolerability of docetaxel as a single agent in the treatment of advanced non-small cell lung cancer (NSCLC). Forty-four patients with metastatic and/or locally advanced NSCLC received i.v. docetaxel 100 mg/m2 every 3 weeks for a median of 4 (range 1-11) cycles. All patients received premedication with oral dexamethasone 8 mg twice daily for 5 days starting the day before chemotherapy. Seven partial responses were observed among 35 evaluable patients, and the overall response rate was 20% (95% CI 8-37). The median response duration was 5 months, median survival time was 10 months and the estimated 1-year survival rate was 42%. Treatment was generally well tolerated. Febrile neutropenia occurred in 10 patients (23%); neutropenic infection occurred in 4 patients, and led to 2 toxic deaths (both patients had borderline exclusion criteria). The corticosteroid premedication effectively reduced the overall incidence (34%) and severity (4% severe) of fluid retention, and delayed the median time to onset from cycle 4 to cycle 7. This study shows the promising efficacy of docetaxel as monotherapy in advanced NSCLC, and combination chemotherapy regimens incorporating docetaxel are now being evaluated in this clinical setting.