Platinum-based combination chemotherapy has become the standard treatment for good performance patients with stage IIIb and IV non-small cell lung cancer (NSCLC). However, newer agents such as gemcitabine and paclitaxel appear to have superior single agent activity and are more easily tolerated in comparison to the older platinum compounds. Therefore, we conducted this phase II study to evaluate the activity and toxicity of the combination paclitaxel and gemcitabine in advanced NSCLC. Gemcitabine was given at 1,000 mg/m(2) intravenously over 30 min followed by paclitaxel at 110 mg/m(2) intravenously over 1 h on days 1, 8 and 15 every 28 days for a maximum of 6 cycles. Between April 1998 and June 1999, 40 of 42 patients entered were eligible and received chemotherapy. Data was available on 39 patients. Toxicities included Grade 3/4 neutropenia in 43% of patients, while thrombocytopenia (13%) and anemia (7%) were less frequent. Five (12.5%) patients developed neutropenic fever. Four (10%) patients developed bilateral interstitial shadows with hypoxia suggestive of a drug-induced pneumonitis. There were 4 treatment-related deaths (1 from pneumonitis, 3 from neutropenic complications). Five patients were not evaluable due to early death. Therefore, 34 patients were evaluable with 12 (35.3%) achieving a partial remission and 1 achieving a complete remission for an overall response rate of 38.2% (32.5% on an intention-to-treat basis). The median progression free survival was 107 days (range, 14-391), median survival was 148 days (range, 12-495) and 1-year survival was 26%. In conclusion, weekly gemcitabine with paclitaxel in patients with advanced NSCLC is an active regimen; however, toxicity and poor survival precludes the use of this regimen as an experimental arm on a future phase III study.