The purpose of this phase II study was to investigate the efficacy and safety of gemcitabine plus vinorelbine as first-line chemotherapy in patients with advanced non-small cell lung cancer (NSCLC). Eligibility criteria included cytologically or histologically confirmed NSCLC (stage IIIB or IV), no previous chemotherapy, and bidimensionally measurable disease. Patients received 1000 mg/m(2) gemcitabine and 30 mg/m(2) vinorelbine on days 1, 8 and 15 every 4 weeks up to eight courses. From December 1997 to November 1998, 70 patients (59 stage IV and 11 stage IIIB disease), with a median age of 59 years (range 38-74 years) were enrolled. The intent-to-treat response rate was 41% (95% confidence interval (CI) 30-54%) with 1 complete responder (CR) and 28 partial responders (PRs), 15 patients had stable disease (SD) and 26 progressed (PD). Median survival was 8.3 months (95% CI 6.0-9.9 months), median progression-free survival (PFS) was 4.8 months (95% CI 3.9-5.5 months), and 1-year survival rate was 33.5% (95% CI 24.0-46.8%). Patients received a total of 229 cycles. Haematological and non-haematological toxicities were moderate. Transient World Health Organization (WHO)-grade IV leucopenia and thrombocytopenia occurred in 13 (6%) and two (1%) cycles, respectively. The predominant non-haematological toxicity was local reactions of the veins in 19 (27%) patients (WHO-grade II and III). Neurotoxicity was infrequent, non-cumulative, and reversible. The combination of gemcitabine and vinorelbine has demonstrated activity in metastatic NSCLC, with response and survival rates similar to those of cisplatin-based regimens and a more favourable toxicity profile that is well tolerated in an outpatient setting.